Recently, I've been running out of space on my PS3, resulting in me deleting various games/saves/game installs. I don't want to buy a new PS3 with a bigger hard drive for various reasons, so I figured a external hard drive is the next best thing to do. I was just wondering what I can actually save onto one. Can I put PSN games, or game installs (which take up most of my memory) onto one, or are they only really good for if I have lots of video/music/photos (which I don't)?

The next best thing is a bigger internal drive. AFAIK, all PS3's can have their HDD replaced with a bigger one. It takes 2.5" laptop HDD's.
Cheaper, more practical.

replace your internal HDD and enjoy the extra space.

Yes all your p0rn can be stored on an external HD... it's actually the best way to store your p0rn..

This

But make sure you carefully back up your data. (I've never done it so you're gonna have to do your research)

I had this problem a while back. This is what I did, and maybe It works for you.
I didn't have an external hard drive and just bought a 500gb internal HD. Then I bought a $4 external inclosure for it and used it as external hard drive to back up my PS3 60GB HD. I then move the backup files to my computer. I re-formated both drives and used the 500gb as my new PS3 HD. I transferred my back up files to my 60gb HD and used it to restore my old data.

This option is great if you don't have an external HD already, or if the external HD you have now is not big enough to back up your PS3 files. Hope this helps.

thats very funny but you don't download porn you just watch them, get off, and move on lol.

seriuosly though. can you use an external hardrive cause i've been wanting to get a 1t hardrive! ok i may not need that much space but its great to have options.

i'm not talk'n flash drives either, but if the op is interested any flasdrive would work perfectly but i've never seen one with over 32g.

first off: what the what? 

and secondly that sounds like a hell of a llot of work! i was wondering what kind of exturnal hardrive i could use? would any work , caue i want to get a 1t external hardrive.

thats becuase your crazy lol. seriously why buy another one when there are other options?

Just ask the person working there if you can install it into a laptop or something, if it's compatible with a laptop, it's compatible with a PS3

My friend recently bought a 1TB external HDD... He intended to open it up and use the inner part (the actual HDD) for his laptop, it turned out that it was a different format and wasn't compatible

And @the bolded, if you don't care about your old data, you can just take out the inner part of an external HDD and put it in your PS3
If you want the old data (saves...etc), just back it up before you replace the HDD