Woo! Felt that one. Just waiting for the stats on it from GNS, will update as soon as I have them. Must be quite local.
EDIT: Yup, quite local - 10km northwest of Porirua!
The following earthquake has been recorded by GNS:
Reference number: 3212649/G
Universal Time: 2009/12/22 19:09:56
Local time (NZDT): 08:09 AM on Wednesday 23 December 2009
Latitude, Longitude: 41.04S, 174.73E
NZ Map Grid (E, N): 2655000, 6018000
NZ Trans Merc (E, N): 1745000, 5456000
Location: 10 km north-west of Porirua
Focal depth: 50
Web page: http://www.geonet.org.nz/earthquake/quakes/3212649g.html