Actually, just had our first commercial release listed on iTunes this weekend.. although you can easily download most of our music for free online.
Check for these releases:
Sound Scientists - Instrumentally Sound (free, but also available on iTunes, GrooveShark, and coming soon to Amazon, Rhapsody, Pandora and more)
Sound Scientists - Raw Materials Vol 1 (free, currently only on Grooveshark and links to album download on HipHopProduction.com)
Sound Scientists - Show Money Mixtape (free, right now only have links on HipHopProduction.com)
There are a few other releases floating around out there, but the above three are our main collections so far.
Thanks for the shout out!