MySQL and Solid State Disks on EMC
Typically any OLTP database that can't fit into memory has random reads.  If you are reading that much from your OLTP database that you need EFDs (what EMC calls SSDs) then you need to first look at putting a LOT more RAM into the database server.  It will be a lot cheaper to prevent the reads than to make the reads faster.  Those EMC EFDs run about $20k each.