We have this, and it works pretty well: http://www.amazon.com/Graco-Blossom-Boo ... B002TUTQMM
Note that you can't put it on a dining chair with arms.
For going out/travelling/backup/outside/visiting toddlers/whatever, we have this and it's great but you need a bag that fits a fairly stiff ~1'x1' square if you want to carry it around inside a bag: http://www.amazon.com/dp/B004L2JJ6O/ref ... 1_ST1_dp_4
Very happy with both purchases. I don't generally believe in going to restaurants with a baby that don't have booster/high chair seats already, because it's often a good indication that they don't want V there, but we've used our travel one in hotels and also a couple of very casual restaurants with other little kids present where we didn't want to bother anybody to find out if they had boosters etc. It only takes ~30 seconds to set up and works great.