I need to add a second tuner to my MythTV Backend (Recording conflicts are becoming a serious PITA), but i'm completely out of PCI slots in my box. I have a PVR-150 in my box now.

So my options (as I see it, feel free to suggest others)
1) Install an additional PVR-150, and move my NIC to a USB adapter.
2) Use a USB Capture Card.
3) Use a PVR-500 with dual-tuners onboard. (I hear the newer PVR-500's tho aren't very linux-friendly).

I'm leaning towards #2 right now, but can anyone suggest a food linux-friendly USB capture widget?

I'm using the 500. I had trouble getting 2 500's working in one machine, so I just moved the second to a second machine that had been using a 250.

Mythtv seems perfectly ok with the 500 though.