I'm all for it Droll.
I've had 4 Xboxs die on me. The first one died within 2 months of me getting one when they were first rolled out. Because it was within the original 90 day warranty that Microsoft provided, it was replaced and I kept my Replacement Plan. The second started going, so I exchanged it and upgraded to an Elite. The first Elite went after a graphics (E84?) error. Then this last one was the RRoD. So, I've spent $210 total on the replacement plans. Considering the cost of replacing the Xbox machines that have failed would easily be 4 or 5x that amount, I'd have to say it's worth it. And keep in mind this last one technically didn't cost me anything since I was refunded the original cost (479.99) of the Elite and replaced it with the new one (299.00). However, I forgot to return my HDMI cable, which the new version of the Elite doesn't appear to come with.
We bought our Whirlpool Duet Washer and Dryer from Best Buy. Within 2 months, the washer had somehow managed to suck a sock up into the intake (somehow). We called the Best Buy hotline and they had a repairman out within 2 days who was there for about an hour before he decided to check the intake. I don't even want to know the cost of that repair had we not had it. TOTALLY TOTALLY TOTALLY worth it. Paid for itself in that one visit.
My wife had a laptop and we bought the two year plan. If you bring the laptop in for repairs a 4th time, they replace it. My wife went from a heavy-as-hell P4 Gateway with 512mb of RAM and crappy harddrive to a dual-core, 2GB memory, Vista machine (we don't mind Vista). Granted, it was crappy for her to be without a computer while it was being repaired, but the laptop was totally free.
So yeah, I'm a proponent of the Product Replacement/Protection Plans. Absolutely worth it. We have one on both of our TVs (however one has to have expired), our HD video card, our washer and dryer, and the Xbox 360. I'd rather pay 50-250 (depending on the purchase price) and have it repaired/replaced then decide not to spend it and be out of that cash.