Transition timetable for Obama
http://news.bbc.co.uk/1/hi/world/americas/us_elections_2008/7712622.stm
KEY DATES
9 Dec: Deadline for states to resolve issues such as recounts or challenges.
15 Dec: Electoral college electors meet in each state to formally cast their votes.
3 Jan: The 111th session of Congress begins.
6 Jan: Joint session of Congress to count electoral college votes
Before 20 Jan: Mr Obama and Vice-President-elect Joe Biden must resign as senators representing Illinois and Delaware respectively. If they do this even earlier - before 3 January - their successors will have seniority over other incoming senators.
Seniority can impact on committee allocation and office space, among other issues.
Thanks STARWISE.