Open source commercialization strategies/ patent-ability

Hi,

I'm building an app that utilizes a lot of open source software. however, the web interface and daemon are written mostly by hand. I'm concerned about protecting my IP. I'm not sure what the patent-ability of this idea is since it is just a combination of a lot of different open source projects, still have to talk to a lawyer about that. I'd like to keep my code proprietary however, use and allow my app to hook into open source.

Can someone shed some light on this subject? What do other open souce projects do?