Proposition Bet: I'll work on your startup for free

Here's my proposition:

a) You're a startup that's pre-series A or less than 5 people

b) You're using a technology that I'm familiar with (Javascript or Ruby)

c) You use an OSI-approved license and release the portion of code you want me to work on

What's the catch? I want to work on interesting projects for small startups, and my employer sponsors me to spend a portion of my time working on open source projects.

Also, I believe it's fundamentally in the best interest of most startups to release as much source code as they possibly can, both altruistically, and for selfish reasons like building an ecosystem and public relations.

Other people are obviously welcome to join in, since it'll be open license and publicly available. Thoughts?