Read "Why Software Patents are Evil" by Simon Phipps in InfoWorld.
It's an excellent summary of the problems caused by patents applied to software.
There's a great TED Talk by Johanna Blakley on "Lessons Learned from Fashion's Free Culture" which reinforces the essential point.
Software patents don't help anyone. The open source movement is evidence that folks working outside the constraints of patent lawyers are more innovative and produce high-quality software. The Internet is built on non-proprietary technology (TCP/IP and related protocols), GNU/Linux, Apache and similar software componentry. How have patents helped?