I already own an Xbox 360, Wii, and a PC. 
Would it be worth it to get a ps3 if I'm hooking it up to my monitor?

I play my 360 almost exclusively on my 22" monitor.  It's great, only thing is I wouldn't want to play splitscreen on this otherwise your golden.

someone asked a similar question on the forums a few days ago and people told him that a console and a computer monitor arent good together.. 

" someone asked a similar question on the forums a few days ago and people told him that a console and a computer monitor arent good together..  "

I played my PS3 and 360 on a 22" monitor when I was in college.  As long as you are using HDMI or HDMi-DVI cable, you will be fine.  It looks great.

I've got this exact setup and it works great for me. My only gripe is that I can only do 720p, but I dunno how much of a difference it would make to be able to go 1080p. I think you need at least a 24" to get that.

I've got a monitor that can work as a TV with HDMI slots and a PS3 hooked to it - looks and works great, so...

" I've got a monitor that can work as a TV with HDMI slots and a PS3 hooked to it - looks and works great, so... "

I do the same and it looks great.

Blu Ray movies will look better than a regular DVD, but with a small screen and the PS3's ability to upscale DVDs, the difference will be minimal.

" I already own an Xbox 360, Wii, and a PC.  Would it be worth it to get a ps3 if I'm hooking it up to my monitor? "

Was about to ask a similar question.  Mind, I don't have a PS3.   May get one someday, but there are other priorities at present.  Currently, I have a PS2, a Super Nintendo, and a 360.  I my 360 hooked up to a 16" monitor, but I sold that 360 along with the VGA adapter.  That monitor died, and I have a 17" monitor now, but it's not flatscreen like the 16" was.  I'm pondering either getting another VGA adapter, or getting a widescreen monitor with a HDMI input and a cheap HDMI cable, or a cheap HDTV.  Probably go used, whichever route I go if I make the purchase in the near future.  Getting tired of being stuck on the 20" RCA TV that has the screws in the back that predated coaxial cables (that at least is equipped with a coaxial input.) 

I play all games on my 23" 1080p monitor. Best gaming experience I could ask for.

I use my PS3 with my Samsung 22" 1080p monitor and it's amazing.

Depends on if your monitor has sound input. I've heard of tons of people who hook up consoles to monitors only to realize there's no sound. 

I'm sure it will look just as good as your average HDTV, provided you use HDMI, and your monitor supports sound input like Geno said. 
 
and in general, right about now is the time you should look into buying a PS3, considering all the games coming out!  Uncharted 2 just came out, Ratchet and Clank comes out in like a week, God of war 3, etc etc.

Just make sure your monitor is HDCP compliant!
If not you'll have to use a Component to VGA box like I have to 

How do you know if your monitor supports HDMI? I've got a USB port under the monitor so would they be it? (As opposed to the USB ports in the side which is used for general things).

" How do you know if your monitor supports HDMI? I've got a USB port under the monitor so would they be it? (As opposed to the USB ports in the side which is used for general things). "

" How do you know if your monitor supports HDMI? I've got a USB port under the monitor so would they be it? (As opposed to the USB ports in the side which is used for general things). "

Here's how it looks hooked up:  
 

One thing to remember with the sound:
Go to the Windoze Master volume controller (Controla Panel > Sound and Audio Devices > Device Volume > Advanced) there selcet Options > Properties and click the button to show "Rear Blue In" and then un-Mute that bad boy. This may be completely obvious to everybody, but when I was setting my PS3 up through the comp I missed it like a dumbass. :P Kept wondering why the sound wouldn't come out no matter what I did.

I play on a 24" monitor, it's not bad at all.