RAID 0/Striping: This takes 2x (size of the smallest hard drive0) and makes it one big drive, in your case, 148GB. The advantage is speed since both drives are written to or read simutaneously. The massive drawback is that if one drive goes, the entire array is shot as far as your data is concerned. The reason behind this is because since the drives are seen as one massive drive to the OS, half the data is on one drive and half the data is on the other. Since the RAID controllers on most motherboards outside of server-class ones don't tend to have a processor for the controller or dedicated RAM, the regular CPU must process this, and it may not feel any faster.
RAID 1/mirroring. Basically, this copies the smallest drive size to the other in the array. If one drive goes, you've got a full backup. The cost is a hit on speed, which you may notice a little more than you would with RAID 0. Additionally, in your case, you'd only have 74GB of storage. Again, as with RAID 0, you'd have some performance hit due to the system having to process things. This wouldn't be present if you happen to use a high-end RAID card with it's own processor and on-board RAM. The downside there is that those cards tend to run at least a few hundred dollars.
I've tried RAID 0, and for all the talk about it, I couldn't tell a difference. Quite honestly, I don't think it's a very good RAID simply because there's no redundancy at all. If you understand the risks involved, and keep a solid backup regiment, then you'll be fine. RAID 1 does back things up, but that doesn't mean you shouldn't back them up yourself. Hard drives are mechanical and will at some point in time fail, so do not rely on any form of RAID entirely.
For me, RAID was simply a waste, but if you're curious to try it out, go for it. Outside of SCSI drives, the Raptors are the fastest drives out there.
