2mm. Although I haven't seen written confirmation, or tested, the following from Digikey should work; (prices from Jan-Apr2002 catalogue, obviously subject to change)

For a ribbon cable;
2 off ASA08K-ND - Tyco/Amp 8 position Receptical, IDC (Amp# 1-111626-6) : $2.39 ea.
1 off WM11-5-ND - Molex 1mm pitch Round conductor flat cable. (5 feet appears to be minimum quantity, and this is 10 conductors, so you'll have to carefully peel 2 away) : $4.60
1 off 3M11108-ND - 3M pin stip header, 2mm, 8 contacts (3M # 151208-8422-TB) : $0.83

For a through hole pcb mount:
1 off 3M1008-ND - 3M 2mm vertical socket, pc mount (3M # 150208-6002-TB) : $1.04

For a surface mount pcb;
1 off SPE1031-ND - Specialty Electronics, Dual Row Top Entry 2mm Receptacle, 8 contact. (SE # 205-04-1501) : $1.34
( *** This is similar to the connector that is attached to the short flat cable that came with the Sv6 *** )

Or you could look at Hirose "DF11 Interconnect wire" in conjunction with their A3B series crimp housings. You'd need to buy 8 of the wires in your desired length, with the desired connectors already attached, and the 8 position housing (s). Very flexible - , eg you can order each wire in a different color, and with different termination options, socket single ended, socket to socket, socket to pin etc. You have to assemble the cable yourself obviously.