Yep, I used to complain about that w/ my old Palm devices, but the batteries seem to last for years - switched to an iPod Touch early last year - of course, same issue -
Now a new iPad2 owner - from the previous statements (and assuming a good battery to start), sounds like you're more likely to replace the iPad w/ the newest generation before the battery goes?
But I was curious if your battery did go after say 3 yrs or so and w/ the device out of warranty, whether one might attempt to open it up and take a look? Looking at the iPad, I see no screws at all, but since Apple can replace the battery there must be a way to pop it apart (might need a special tool?).
Would be interested to hear thoughts from those who may have given this a try w/ an older iPad? The battery(s) must be much smaller than those on a standard laptop but also be curious as to the number, size, and 'real' cost - a $100 is a lot relative to the cost of the iPad -