It won't be everyone's cup of tea, but I picked up a little PDA holster at Lowe's (building supplies) last night for $3.95 USD on clearance. It's heavy-duty, roomy and provides elastic side pockets for tools or other accessories. It's meant for construction use but could be for general purpose too.

It's called the PDA HOLDER, Field Pro Series, from a company called Texas Hold-ums. They make other varieties; here's a provider:

http://www.abccatalog.com/store/list...idCategory=168

I saw some of their products on ebay as well.