A listing of lists you have voted for(and/or commented on), for example: "Your votes/comments" under the "My stuff" tab.
Added on May 16 11:27
Its in there but scattered amongst a lot of other things and there's no way to filter it. Tom is working on being able to make lists of lists and this could be one that was auto-generated, similar to how, whenever you Favorite a movie, it gets added to your Favorite movies list. There could be lists named "Lists I've voted for" and "Lists I've commented on," (with the ability to sort by how many comments you've made) and "Lists I've voted for and commented on"
You can filter it, you just click the list vote link in the box on the right. Most likely I will add a better way of viewing these lists anyway in addition to the lists of lists functions Hyomil mentioned.
Ah, I was only using the 'My updates' link in the upper right blue box on the front page accessible through 'view all' (or in your profile under Edit Profile > Updates). The 'My updates' link under the 'My stuff' tab at the top of the page goes to a different page entitled 'My feed,' which has different content and links for filtering. I'd suggest either giving the two links different names or combining the content of the two into one page. But if you combine them, it would be good to have a separate RSS feed for the 'My updates' page (which currently has none).