I spotted an old forum comment already about this. I'd have responded then about how great an idea this was, but I wasn't here yet!

I'm learning Chinese from a few websites, and am learning characters and pronunciation exclusively here (for the time being). When a new character pops up on the practice screen, many times this will be the first time I've ever seen it (unless it's also a Kanji, but that's beside the point).

I'd like to be able to tag items that look or sound similar in order to review them apart from the large lists I'm using. Maybe the best mechanism would be to put a "difficult word" checkbox near the practice window, which when checked would add that word to a new cram list. I could then back out of "Practice All" and concentrate only on the difficult word cram list for a while until the differences become clear. Does this make sense?

This is a great idea, because so many words have the same radicals in them, this would be VERY helpful!

It is done and in alpha testing. You click a star next to the word or character, and it goes into your 'Starred Words' list, which you can view or practice. I'll add you guys to the alpha tester later today and you can try it out.