Here's my understanding of the situation, based on another thread <http://www.internettablettalk.com/forums/showthread.php?t=11695>;

The N810 takes miniSD cards; you can use microSD cards with an adapter.

The adapters are functional with BOTH SD and SDHC cards - there is no difference between adapters (they just change the size/shape from micro to mini/regular).

The N810 can use both SD- and SDHC-format cards (but in mini and, with adapter, micro size - no full size cards).

While my N810 hasn't arrived yet (developers delay list ), I don't believe there are any card adapters included. Look on the link above to find stores that sell adapters. They're cheap, and can convert microSD to mini, full-size, and even Sony MemoryStick Duo. And, you can convert full-size SD to Compact Flash. That should cover everything!

Hope that helps. It sure helped me.