I've found a rather interesting product, the Enhance Technology QuadraPack Q14.
It houses 4 2.5" hard drives in a 5.25" drive bay with active cooling (40 mm fan)
Some (basic) reviews:
- InformationWeek
- Tom's Hardware
Just imagine: four (RAIDed) high performance HDDs, such as the Seagates's Savio (10k RPM) in a single 5.25" bay (ideal for SFF systems): Jaw-dropping performance with lower space/power requirements than 3.5" drives. The only issue is the (relative) high cost of this solution and low storage space. Storage space shouldn't be an issue using external HDDs/DAS/NAS for high storage demands (backups, photos, video, music, P2P)
What do you think, folks?