I've often thought something like this would be useful, but I'm missing a few things (and you have a bug, I can't leave my e-mail blank because it says that e-mial is already taken).
1 - I can't figure out how to add a bookmarklet. I can only add you page
2) I wouldn't go to a page to enter in the sites to save, that is too much of a pain in the ass - a browser plug-in would be much better.
Right click (or the equivalent on your platform) on the link labeled MarkitForLater Bookmarklet, and add it to your bookmarks. Optionally if you have the bookmark toolbar enabled in your browser you should be able to drag that link to it.
Can you elaborate a bit on #2? I'm not sure I get what your getting at.
Edit: And thanks for the bug report, that should be fixed now!
1 - I can't figure out how to add a bookmarklet. I can only add you page 2) I wouldn't go to a page to enter in the sites to save, that is too much of a pain in the ass - a browser plug-in would be much better.