Love the groups. It took me at least an hour yesterday to organize everything, but it makes trading a lot easier.
But..
I was wondering about a sort feature.
Here are the sortings that I would like:
Adoption Date - original adoption date, which is what the sorting is on now
Traded Date - the latest trade, which would be the one for the current user
Type - dogs, rats, horses, holidays, custom, etc (though you could do this one with groups)
And, of course, a reverse sort option for every choice.
Really, I think the traded date would be great! I have the hardest time finding new pets sometimes, because they'll be a couple of pages in because of the original adoption date.