We prefer the smaller picture, because otherwise it distorts the frame, and makes your posts harder to read. your best bet is to find a thumbnail of the picture you like. When you see it on a site, right click on it. You'll get a menu, at the bottom is "properties" click on that. it will pull up a new screen, you'll see a section that looks like a web addres (as in:
http://whatever.com) highlight that, then right click on it. click on copy. Now go to your profile, click on edit your profile, go to select avatar. you'll get another sub screen. at the VERY bottom of the acreen is an area for you to put in your own url code. erase what is already there, right click in the area, select paste. then click on use this avatar, update your profile and there you are! This same idea works for signatures too, only you have to put this in:
[img]
http://whatever.com[/img]
what is important is the brackets and img's <img src="/images/graemlins/smile.gif" alt="" />