I noted total SL Resident Numbers back on the 28th June 2006. At that time there were 298,407 residents. By comparison, now there are now 396,651 of us (give or take an alt or two). Therefore 98,244 more residents in only 44 days, an average of 2233 new residents per day! Whoo... crazy.
(Edit: Only a couple of days later the total number exceeds 400K)