The hardest part about building a successful social news is building the community, good luck. Getting marketing and advertising people to remember u-n-d-r-l-n dot com is going to be an effort in itself.
Really? Have you read Positioning (Ries and Trout). Certainly branding is more than a name, but for marketing you want something that is at least easily transferable by word of mouth, no?
Yup, I've read lots of their stuff (particularly Ries).
Our firm has named a number of companies. In my experience, these are tough projects, as it's difficult to determine which is objective/subjective feedback.
Some of our most successful names were ones that clients hated initially, but later found very usable. Although some are put-off by names that feel different at the outset, once they are spoken a few times these ones often become more memorable.
I like undrln because it’s short, and there’s a bit of a tongue-in-cheek nod to the tools we use every day in it. Seems to be working: http://search.twitter.com/search?q=undrln