How about Gene beig transported to 2007?? What a brill spin off series that would make. Tho thinking about it he would probably get 15 years in jail in the first 5 mins for some of his un-pc comments, wouldn't be much of a programme after that!!
Sam is in a coma in 2006, dreams that he is in 1973 and looking for his real father. It turns out to be Gene Hunt - the clue was there all along ( Gene Hunt !!! ) . He eventually wakes from the coma and goes in searh of Gene in 2007.