Some time ago, the gadget websites posted a link to some empirical testing of netbook batteries. The observant reader will note that my netbook, the Dell Mini 9, fits in about halfway down the list. What's interesting about these results is that the Mini has the smallest battery capacity of all the netbooks on the list.
The Asus 1000H has double the battery capacity of the Mini, but it also has a regular hard disk. It only gets an extra 20 minutes or so of battery life (the other specifications are mostly the same as the Mini).
From this I think we can conclude that solid state drives are more power efficient than their regular counterparts in laptops. This was a common belief before an article in Tom's Hardware claimed they weren't; if we believe the results in this test, which might be a little bit more indicative of real use, rather than the tests used by Tom et al.