Something I incidentally found while surfing on dA:
Bobsmade - art & custom clothing.
They make custom t-shirts, shoes, headphones (love this idea!), glasses, ... by painting (!) your ideas on them. I myself am a big fan of the thought of customized clothes and always wanted to paint my chucks - finally there are people who are doing it professionally and from whom I can learn ;)
However, for those of you who can't draw I highly recommend this site.
I think the prices are absolutely fair - measured by the hours of work and the effort they put into every piece of work.
Their designs are also fun X3 so colourful! :)
Speedpainting video of customized headphones:
Click to view