First of all, I really want to release the code to a few of the projects I use internally but my biggest worry is that people will come along and pass off my code as their own. I've come to realise there isn't really a way around this, no matter what line of work someone is in. If something is available, there will be someone, somewhere that wants to steal it. Luckily, this only accounts for a small minority of the people I'm trying to attract.
Most of my projects have some sort of financial gain for me, such as my CSS Compressor, and by releasing the source code I'm essentially risking the chance of loosing potential income. However, I'm not interested in making direct money from some of work my work; Instead I simply want recognition and more work to put on my portfolio, which to be honest, if quite bare right now.
I'm slowly releasing projects one at a time to my Github account, but it's a time consuming process and it's hard to find time. Another option is to collaborate on an already existing project, but I'm finding it hard to find anything I'm interested in that doesn't already have the features I'd want. Hopefully I'll find more time to update more projects, but for now you can check out my CSS3 Buttons and Feed Parser for an idea of what I'm working on.
Feel free to request any projects, or suggest any ways I can get into the open source community a bit easier based on your personal experience.