Well, we could look at WLAN MAC address of first units sold in October/November 2005 (i.e. from developer program) an units sold few week ago and try to guess something from that. But this implies numbers are consecutive and there are no holes (not used or used for other devices). First few bytes (4) are identical and mean manufacturer and probably model - maemo download pages check for it when downloading firmware so there must be pattern. The page accepts any code between 0014a7fa1d00 and 0014a7fcXXXX (I.m not sure about last XXXX, was lazy to try). My id is near 0014a7fa21XX and got in in November 2005.