I realise it's been done, but... the question is, can it be useful?
Ok... For this experiment, i used 3 identical PNY 2 gig USB flash drives.
To start of with a baseline, i ran an XBench disk test on a single, freshly formatted drive:
Ok, that being done, lets plug in all the drives. I plugged the three drives into a USB hub, and fired up Disk Utility.
I set the array up to use all three drives as one big drive. This should give an increased read & write time. ...In theory, at least.
All 3 drives mounted separately
The newly formed array:
Running XBench again, on the array:
The XBench tests, along with my highly unscientific test of copying a large image file to a single drive, and to the array indicate a significant speed increase when the 3 drives are RAID'd together.
Now, to answer the question i posed at the beginning of this post. Can it be useful? Well, that's questionable... but, this was fun!
Looking at the above results, you may notice a decrease in speed of the RAID array. This is due to it being plugged into a USB hub. With each drive plugged into it's own port, directly into my G4, there is an overall increase in speed: