I'd suspect the hard drive first, especially since the problem started when the computer was moved while the drive was on. When you say the "driver tested as fine", how did you check it? The fact that Disk Warrior couldn't complete a repair sure indicates a problem with the drive.
Can you boot to the system DVD successfully? Or an external hard drive with a compatible system on it? It appears so, since you say you've tried Disk Utility and Disk Warrior. While DW was running, did it throw up any messages relating to disk malfunction? When it failed, what did it say? Or did it just freeze up the computer? You can check the system log on the system you ran DW from (not if it's on a CD, but if it's on a hard drive) and see what else got logged.
If you do have an external drive with at least 10.4.11 on it, download and run SMART Utility (find it on versiontracker.com). This will tell you for sure if your internal drive is failing (well, 95% surety). Disk Utility's SMART status indicator is not good enough.
If you need to recover your data, can you boot into Firewire Target Mode and copy your stuff off to another computer? Then try reformatting the drive; do a repartition too (Apple Partition Map). But I don't personally think this is worth it; the drive is old enough that it would behoove you to replace it anyway.