Dont get one! The FCC is going to ban them next year unless they are "flag compliant"
VA hit it on the head (as usual)
I'm not sure "don't get one" is quite the answer =) Yes broadcast flag is more than little uncool, and there is some legislation coming into effect... but
a. stuff manufactured prior to that date is grandfathered in
b. I'm sure cable companies have the ability to update the firmware on the digital cable boxes right over the line
see
eff's page on DTV and broadcast flag-- crash, the main reasons to go to digital cable are PPV movies, and getting the movie channels... I've got digital cable, and use it in conjunction with my TiVo but I never watch a channel "higher" than 73... (i just use analog cable for my homebrew PVR upstairs) some of the other bells and whistles of digital cable, are moot with a PVR (the guide data, etc)
*shrug* It's much easier to just put the coax into the back of a TV tuner card for analog cable, but you can control an external digital cable box via serial/IR blaster (as VA mentioned) it's just a little more effort.
good luck!
rampy