[vineweevil1]

I bought my tom plants last year but decided to grow some from seeds this year.  I started them off last weekend in a heated propogator in the house and despite the germination times stating 7-21 days most of them are up. 
The seedlings were getting taller each day (but still only have two small leaves) so I have turned the heat off, is this the correct thing to do?. The are only 2-3" tall.
Thought they might get leggy if I left them to grow on heat much longer.

[Aunt Sally]

They need the best possible light to stop them from becoming leggy and not to hot 16-18^oC is high enough !

When you prick them out plant them lower in the pot as they will produce roots from the buried stem.

[GreenOwl]

Yes, turn the heat off.  Put the seedlings on the windowsill and follow DD's top tip - prop cardboard covered with tinfoil to reflect more light onto the seedlings. 

(Thought I'd save you posting it DD!  )

[Aunt Sally]

The RHS have some good advice here :  http://www.rhs.org.uk/advice/profiles0600/tomatoes.asp

particularly how to prevent damping off when pricking out !