I have a few extra invitations left for both Evernote Web and SocialThing. While both seem to be great services I have few comments thus far about either.

Socialthing seems to be a good service, but at least in my opinion its similar to FriendFeed which has more to offer.

Evernote seems to offer a service that I will likely continue to use, although that is based solely on a quick first impression as I only received my invitation yesterday. (credit to (jeff)isageek for my invite)

Either way I have a few invites to each service, just in case you want to make up your own mind. Hit me up by email: areyouageek (at) gmail (dot) com