RE: Counter Height High Chairs/Booster Chairs
I'm not sure about the hook-on chairs (I do know that they do not work at all tables), but if you have bar stools with a back, you also could use a booster that straps to the stool. We have the First Years 3-in-1 Portable Booster (which I think is now discontinued) and think it's great. You could use it with the tray or without. There are several similar seats. Here are some comparables:
http://www.thefirstyears.com/product...sp?pValue=3368
http://www.kmart.com/product/index.j...entPage=family
http://www.target.com/gp/detail.html...sin=B0000DEW8N
Mommy to Justin (13 years) & Ashlyn (8 years)