I use an Air Duster aerosol can. I'm in the UK but the Amazon.com link below shows you what I meam;
http://www.amazon.com/Fellowes-99790-FELLOWES-Air-Duster/dp/B00006I58S/ref=sr_1_8?ie=UTF8&qid=1311678601&sr=8-8
But other than that, I turn the keyboard upside down then shake gently. I'm always surprised what falls out.
For cleaning the keys themselves I use a Keyboard cleaning kit, similar to;
http://www.amazon.com/3M-Keyboard-Cleaner-Kit-674/dp/B00006B7V9/ref=pd_rhf_shvl_3
Mark
Is there a small blower that can clean dust off keys on a computer?

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