You don't even need a hard drive recorder. You can get one that only uses a memory card, and then get one of these:
http://www.adorama.com/MMHG140.html
http://www.compusa.com/products/prod...ct_code=339276
Or something similar. I just did a quick search, but I'm sure they come in larger capacities as well.
The advantages are that the memory-card only video recorders are smaller in size and more conventient to carry around. Then you can just dump the memory card into the hard drive and then continue. Like someone said above, you can record up to an hour on a nice size memory card. So for your vacation, as long as you don't need to record more than an hour at a time, you will be fine. Also, you can always purchase more than one memory card and do a swap while on the go.
Here's a nice one:
http://www.dcresource.com/reviews/so...ew/index.shtml