There's a good sticky in the main Baby and Toddler section that has lots of rhymes and songs to sing - many with actions - DD is just over 6 months and we do lots of singing and action games now, she loves them - particularly eensy weensy spider!

Another thing I would suggest that works well - age old and tested - is kitchen equipment. Wooden spoons, plastic containers, saucepans, plastic spoons etc. I even wash out and hold on to old icecream containers, plastic bottles etc. I let DD play with these, teach her how to bang, how to pick up different bigger shaped items, help her put little containers inside bigger ones etc. I'll often sit her in a washing basket so she can have heaps of things to choose from in the washing basket with her. Just make sure she can't tip the basket she's sitting in backwards.

Thanks for the other ideas in here - I'm finding them really helpful too!