LinkedIn has been doing this for a while and I just noticed it on Slideshare as well: alerting users to the completeness of their profile.
This strikes me as a very subtle yet effective way to get your users to provide more information about themselves in their profile. Who doesn’t want to get to 100%? If there is underlying value to the user, it should really accelerate completion of user profiles by raising awareness and granting some Pavlovian eye candy as well.
If your site invites your members to submit profile type data, you could do worse things than to add a percent complete status bar to your interface.