You sure can, it's called RAID10, 1+0, 0+1, and similar. Essentially you have 4 drives, 2 sets of RAID1 mirrors, then span across them with RAID0. The best solution though is to use a controller which supports RAID10 natively so you don't have to fiddle with it.
__________________ Culley Mail | Dell 2950III | 2x Quad Core 5420 | 8gb RAM | 6x 146gb RAID 0+1 | Red Hat 5.3 | Zimbra 6.0.1 Network Edition Test | HP DL360 G3 | 2x Xeon 3.06ghz | 4gb RAM | 6x 18gb RAID 5 | CentOS 5.3 | Not in use now |