I'm talking dust here. Do you clean yours on a regular basis, if so, how often on average?  Or, are you so lazy that you'll only clean it once you notice a increase in temps? - that's exactly what prompted me today.  I've just finished cleaning mine, I was shocked by what I found, it looked like the inside of a vacuum cleaner. I don't have a clear panel on my new case, as a result I'm finding that dust is accumulating a lot easier, now that I can't keep an eye on things as easy as I once did. 
   
So, how often, and do you actually like cleaning yours?. I found cleaning mine just now was very gratifying, especially after finding the dusty monstrosity inside. 

Well my laptop, Everyday, I hate dust on my crap!

Like.... once a year?

Less often than I should, my fan filters take care of most of the dust though.

If I ever open it to upgrade or whatever I will clean it out with compressed air. Other wise no i don't ever clean it, just maybe the top, back and front with a rag.

Not often enough.  Usually, just when I am upgrading or switching out a part.  Although, I try and keep a good eye on the dust around the fans and vents.  Since I just replaced the power unit over the weekend, I spent some time cleaning it out pretty good, but it may be quite some time before I have to get inside and rearrange things again.  My hands were near black with "soot" when I was done.

Twice a month

The interior once every sixth months or less. The case fans attract dust to the vents so those get cleaned more often though.

Every other month.
 
Reminder unplug everything and dont use rags or anything that might cause a shock. I use compressed air and a dirt devil with plastic attachments that does the job.

Whenever I vacuum the carpet I hit the fan vents too... so about once a month.

When the temp warning starts beeping.

Around every other month.  My room gathers dust like a mofo.

I've had my computer for 2 and a half years and I have never cleaned it. I wipe the front every now and then, but I have used the same keyboard the whole time and haven't washed it.

" Twice a month "

Every couple months. Just as often as I clean as I dust my room...

I'd say once every 4 months. Every time i come home from the dorm and random other times when i notice i can't read the serial code on the graphics card pcb.

NEVER!

I vacuum my house every Sunday so dust isn't too much of an issue. I also have two dust filters on my case which capture most of the crud floating in the air. Outside of that I usually use compressed air to blast out any of the finer caked on stuff about twice a year.

Once or twice a year.

I really need to open up my tower and clean the dust out of it.  I haven't done that at all since in got this computer back in June 2008.

...this thread reminded me to do it now

I have to clean out the front three dust filters every week or so. I have the three bays they're attached to permanently unscrewed so I can just slide them out easily. I probably don't need to clean them that often, but the thin layer of grey dust that gradually accumulates on them really bugs the hell out of me. As for the interior of the case, it doesn't get too dusty, but I give it a going over with a can of compressed air now and again, just to stop any build up of dust that might cause any overheating.

Clean?  

Well I clean the dust off the outside everyday.  Internals i give it a blast of compressed air say once a month, I'm fairly anal about dust in my gear.

"

This was taken around christmas (Ignore the dateline). It's still not  been cleaned. "

I wipe off and sometimes vacuum the many many fan holes where dust likes to collect whenever I notice a lot on the case. The inside is still pretty well kept.
 
I keep some hand sanitizer handy so my input devices get a wipe-down every now and then when I notice gunk or grease.
 
Sadly I take better care of it than my teeth.

I have only had my PC for 5 months or so, I should probably clean it out. I get the impression that simply spraying a can of compressed air at the dirt is the way to go? Anything else I should look into?

When the temperatures rise or when I'm replacing hardware.
 
I recently found out my GPU was running at 108 degrees! 
I took a vacuum to the heatsink and it's sitting at a comfortable 50 degrees idle and 80 degrees max in game.

In the past? rarely, if ever.
 
I learned the error of my ways after my videocard pretty much died of heat stroke and when tinkering with that I realized my CPU fan was a total fucking mess.. Since then I've bought a new case (Antec 900, much better airflow), turn my PC off regularly and dust out the nooks and crannies every few months.

" turn my PC off regularly "

Since the Antec 900 is such an old and outdated case, I had to install my own dust filters on it. They help out quite a bit, but some stuff still gets through the corners. I'd say maybe once every 3 months I take it out and give it a good cleaning; maybe switch around some of the interior components on a whim, while trying to improve airflow and cable management. I also live in a horribly dusty place : \

wen I upgrade my PC because all the dust is annoying when I have to do something inside my PC

I just stick a toothbrush between my laptop keyboard but that's it. Oh and wipe my screen after my spit has become noticeable.

Once a month.

" @Three0neFive said:

" turn my PC off regularly "

Woah woah woah there... are you insane? Mine runs as my all purpose media machine even when I'm using my consoles. It would be completely dead in here without it. "

Once a week.  It's a laptop, I use a q-tip to clean in-between keyboard mess and a piece of cloth to clean the screen.

About 2 or 3 times a year.

I don't think I ever cleaned the dust out of my desktop. Not until 3 years after I had it and the hard drive needed to be change.

Pretty often. Every time I open up the case, for one thing. I don't actually need to clean it that often since its all water cooled, but I do have a cat, so there is plenty to clean anyway.

Oops. Thanks for reminding me.

 http://www.overclock.net/computer-cases/690284-what-5-years-smoking-does-your.html
 
Have a look at this :P
 
Don't smoke around your PC people other wise it will look like this guys.

Maybe every.... 4 years?
 
Well, I was shocked at how much dust got caked into the poor thing.
 
I'm probably going to clean it much much more often.

I used to do it regularly, now, not so much.