Wishlists are a practical things, proof, pretty much every respectable online store offer them. It's a cool feature, but keeping a list of all the wish lists on all the sites isn't really practical, in the way that you can't have the newest 780i motherboard and your pair of fuzzy slippers on the same list.
But then, straight outta Web 2.0 Town, Wishlistr comes out and blows our mind, and gives a new meaning to wish lists. You would think that there isn't really anything to reinvent in a wishlist, and you're right there isn't, but who would have thought of it? The design is elegant, and the whole thing just gets the job done, and the use of Ajax here and there really caught me off guard, and looked pretty slick. The user panel is also dynamic, which allows for easy management of your offering suggestions. From the visitor perspective, the wish list itself is far from impressive, and in fact, I find it pretty plain, although the ability to select through a dozen templates is an interesting feature. Ease of use? Let's say that it's going to be easier for your 6 year old nephew to set up one of these than to ask for daddy to email you a copy, and it updates automatically and you can keep track of updates via RSS, so adding some last minute gift ideas isn't a problem. All you need is a title for the gift, add an optional URL and description, and you're good to go.
Although I liked it from the first time that I tried it, I think that it does need a bit of refining. Being a category person, I would like seeing categories on there very much, and an optional "Price" field for each gift and some "sort by price" feature to even further facilitate gifting. Otherwise, I declare this without a doubt the web discovery of the week.
Check it out:
EDIT: Woops! Marko posted this before me! I guess we had the same idea, didn't we? I hope the link compensates for my lack of originality :S .