Yikes! I thought mine were coming on really well on my "sunny" window sill (except it is still peeing down here...) but my biggest are still only about 15-20 cm high (about 5 or 6 inches). Still they look good so I guess I don't need to be worried yet. In fact one of teh cherry tomato plants has a couple of flower buds forming! even though it is only about 4 inches high!!
I have loads of toms!! About 30 plants!! can't plant them all so I guess some friends will get some giveaways.