I am fortunate in that my commute to work is mostly in the country, as my workplace is on the edge of the city, and I just need to join one "town-road" before I turn straight off into the campus.

So most times when I commute, I use my road-training bike, a Scorpio RA300.

When I have a time trial coming up, I ride to work on my RR/TT bike so I can "practice" on my aero-bars, and do intervals in preparation for the race. Its a Giant TCR.

I would like to get a specific commuting bike in the next year or two - as the younger children get older, I will be using the car less and less (particularly with petrol prices rising). Perhaps one with pannier bags so I can carry my diary and other work with me.