I love grocery shopping too! DS is a bit the same. I find he's better in a trolley, but if it's a pram or I'm carrying he wants EVERYTHING and NOTHING (ie most of the time when he gets it, he just throws it straight away - lovely developmental phase!). And the screeches and whinges if he doesn't get it.... eek! I too love that he's curious, but it's also exhausting. I have even thought of getting a harness so he can have a bit of freedom and walk by himself some of the time, especially when it's a safety issue (like when he's trying to walk out onto the road!). But I also want him to learn he needs to hold my hand sometimes, and that he can't just have everything he wants.

Anyway, just letting you know I sympathise. I find short errands are the key (say, 1/2 hour), and the fewer ins and outs of car seats/prams, the better. Toys and books work only sometimes, he's often better with things he wouldn't normally have to play with (my handbag - all zipped up!, an empty pen case, a water bottle etc). Oh, and Mum to stay at home with him while I go grocery shopping! Here's hoping it's a short phase, lol!