I must say that shrinking of avatars doesn't necessary means shrinking of file size. I can make avatar 110x110 pixels, only 4 kb large or better say, small. If you want me, I can make avatar 30x30 pixels, and 50 kb in size... see ? Biger is not always, larger phisical size of the file... I'm trying to keep all my avatars below 7 kb, and I think I succeded.
WEB page is slow on loading only if you have large and unoptimized pictures. My all pictures are always fully optimized.
I wouldn't shrink anything if you ask me...
Here is your avatar Techie101 shrinked to 100xsomething (from 200xsomething). File is just 1 kb large, but can't see a thing...