I just completed my second run through of inFAMOUS and all i need for the platinum is all the blast shards. I have less than 20 blast shards left and i cant help but wonder, am i wasting my time? 

The blast shards that you get from missions don't count toward the trophy for collecting all of the 300 (350?) shards that are scattered around the city "in the wild".  It doesn't matter if you got the five from the mission or not.  You aren't wasting your time.  You're a bit OCD, maybe, but you aren't wasting your time. ;)

Well do you want to find them?  It's your game, your decision.  How much does that trophy really mean to you?  Personally, I couldn't care less about that type of thing but nobody would look at you differently because you do.  Either way, it's your call man.  If you're enjoying looking for them, go forth and conquer!

"@IceCrystal said:

" The blast shards that you get from missions don't count toward the trophy for collecting all of the 300 (350?) shards that are scattered around the city "in the wild".  It doesn't matter if you got the five from the mission or not.  You aren't wasting your time.  You're a bit OCD, maybe, but you aren't wasting your time. ;) "

are you sure?  "

The ones in side missions don't count towards your 350 total. They are just there to help you get more energy balls to store more electricity without having to go searching. But there are 350 of them in the actually game world that you have to find. 

Wasting your time in the same way that most trophies do...being impossible to compare most the time.

Yeah, any of the missions that give you multiple shards are only there to help you increase your electricity level. I did one after I had maxed my electricity level and had a counter for my shards, and it never increased my count. Only ones you find scattered around the city are counted.

And no, you aren't wasting your fucking time. You're playing inFamous!