Here's my take:
I like Neo's logo of an ON switch. However that logo has been used on several sites, including one of the Stackexchange 1.0 sites onstartups.com. But I like the icon itself a lot so I worked around it. To me the idea of Web Apps is that they reside in the cloud. And for our site's purpose(Q&A, Discussions) I think it's fitting to add a cloud speech bubble concept.
P.S. I believe we're going with the Domain name "NothingToInstall.com"
For the actual implementation on the site, it will be more polished. Please see my design concept post.