3, 627Gb (or 3.6Tb). although, the external drives aren't officially mine - they've been given to me for the next year or so from my university for a project... and they're thinking about my request for a LaCie S25 (another 2.5Tb, potentially bringing my total to 6.1Tb!!!)
All the computers I have access to... that'd be different. But that's a pretty decent start. (Plus, a 20GB drive, a 10GB drive, a 100GB drive, and some others I'm probably forgetting that don't have a computer home right now, for a disembodied total of 572GB, 160MB)
iMac CD: 108GB/160GB
Windows Partition:40.73
Creative PortaBrick™:7.91GB
iPod Video(dead):27GB
Lexar™JumpDrive™Secure:128MB
Thumb Drive:64MB
Compaq Notebook:100Gb(bit heavy after awhile)
1 IBM DeskStar:811MB
1 IBM DeskStar:811MB
RCA Lyra:128MB
RCA lyra:256MB
LG MP3:256MB
Toshiba Gigabeat:10GB
HP Pavilion a500n:80GB
PowerMac G4:40GB
Well my friend's powerbook has 7GB left with a 100GB HDD and she's only had it for 2.5 years so the fact that 75% of my HDD is free really blows people away- including me!
PB 1Ghz 12" 120 GB which comes out to about 90GB.
Nano- 4GB
Home editing and backup drives- .5 TB (by summers end 1TB)
Ofline HDs (media storage) 400GB
I don't own these, but I admin them:
Work media servers, RAID5 and mirror of the RAID5, >2.5TB.
Offline storage, 5TB of 9GB DVD cartriges. (pain in the ass)
Numerous PC workstations with saddly small drives.