The whole idea with raid1 is that you have two hard disks that are exactly the same. If one takes a massive sh*t on you, your system just keeps right on running.
Raid0 is different. Yes, there's an increased risk, if you look at the pure statistics and do the math.
I still have a 6.4gig ibm and 5.7gig maxtor drive. Both work perfectly. If your aren't running raid1 right this second, raid0 isn't going to save you from anything. So, if you're not worried about losing a hard disk right this second, raid0 isn't going to make you lose any sleep. You're not sweating it with one drive, and the chance of a hard disk failure nowadays is like winning the lottery.
The way I look at it is like this: if any hard disk is going to fail, it usually does it within about a year. The majority of people lost at least one 75gxp within the first year, but there were some exceptions. Mine lasted something like 14 months.
Hook up your raid0, and be vigilant about backing up stuff you don't want to lose. With a cd burner, it would take you about 15 minutes each weekend to find all your outlook/favorites/documents and compress them down and burn to disk, if you keep track of where you save stuff.
C@lling it like I c it...