I've been uploading screencaps to my website - www.seshatplace.com/SGCaps/index.php. Right now I've screencaps from all of Seasons 2 and 3 and up to episode six of Season 1. I've also got screencaps uploaded from Stargate: SG1 and several other series/movies that Michael has been in.
The screencaps are uploaded at a maximum of 600 px horizontal but I do have them much larger than that. If anyone would like any of them larger for any reason, please just let me know.
When I do screencaps, I base it off of what I'm likely to use when doing graphics. Since I do SG1 graphics with everyone (well, mostly, you'll notice there's a dearth of anything from Season 6...I wonder why? *LOL*) I do screencaps of everyone. Saving Hope, on the other hand, I very much concentrate on one person.