The first thing is think about who your audience is and what kind of connection they are trying to make with you when they view your about page. An about page for a startup, a freelancer, a blog, etc will all have different audiences and different goals.
If you are a startup, your audience will likely be potential and current customers, journalists with press inquiries, and possibly people looking to fund you. They will want to know why they should use your product, what makes your company/product unique, who are the people behind it, etc.
I'm currently redoing my own about page, and have gathered a few helpful links:
http://eighthourday.com/about/
http://getsatisfaction.com/team/bios
An about page I did: http://www.votereports.org/about
Not an about page but the layout could easily be done like an about page: http://grainandgram.com/
By far my favorite due to the style of the photos: http://mckinney.com/us
Edit:
I also like: http://www.steinway.com/about/
More minimal but extremely functional: http://grandpeople.no/about/
Spotify has a great one: http://www.spotify.com/uk/about/features/