Multi-card USB readers - why is this concept more well played? It IS played though, even though it might not be well spread. Here's a couple for you from Elecom, available in Japan (or over the internet through GeekStuff4U, which is in Japan too, but online, and online is everywhere!) One is the multi-card stand-up reader MR-C27 which reads up to four SD/SHDC or SDXC cards at a time - supporting cards up to 64GB. The MR-SMC06 is a dual-card USB stick or thumbkey which has no internal memory in and of itself but has two microSD or microSDHC slots. Super cute and super handy!
Both of these fine items can be found on GeekStuff4U and I'm sure your everloving nerd friends would just LOVE to have them for a holiday gift - bank on it. The MR-C27 multicard is [here] and the MR-SMC06 seems to be sold out or just gone for the moment, but that link'll find it for you when it's back up.