Just wanted to toss these out for parents. I bought my daughter two tile-laying games from Gamewright and both are excellent.
The first is Legend of Landlock. She was able to play at 4, but she's 5 now and starting to really hone her strategy. LoL is a beautiful game with a children's fantasy undertone (gnomes, fairies, dragons). It's also surprisingly deep--my wife and I actually enjoy this one some nights after girl goes to sleep.
http://www.amazon.com/Gamewright-Legend-of-Landlock/dp/B0000663RM/ref=sr_1_2?ie=UTF8&s=toys-and-games&qid=1200429380&sr=8-2
The second is Hisss. My daughter enjoys this one too, but it's a lot more simplistic than Landlock and relies more on luck of the draw.
http://www.amazon.com/Gamewright-219-Hisss/dp/B00005NQE8/ref=sr_1_1?ie=UTF8&s=toys-and-games&qid=1200429407&sr=1-1
Anyway, just thought's I'd share.
Pete
Legend of Landlock reminds me rather a bit of Carcasonne. While I realise that it is currently being excoriated by some over in the American vs. Euro boardgame thread, Carcasonne has been received quite well in my family, including by my 6-year-old daughter and 8-year-old son. My son still presides forth with his story of winning with a 48-point farm, and my daughter is devilishly crafty with her small cities and short roads (which often plays into the hands of my farmer-king son).
!i!