I saw
this login prompt today. Made me chuckle (well, not really), but it instantly gave me a good feeling for the site - its personality and how I wanted to interact with it.
Now this approach isnt for all sites (and some may call it corny) but it's the page with the hightest drop-off rates of most sites and anything that can be done to minimise this can only be a good thing.
I say bring on the log! :-)
Note:
Brightkite is a location-based social network. In real time you can see where your friends are and what they're up to. Depending on your privacy settings you can also meet others nearby.