Small books - the 'mini library' ones, 4 in a pack so 4 gifts . Water pistols or cars for older boys, glo-sticks / glo-bracelets, skipping ropes, bubbles (various types), balloons. For the babies at DD's first birthday, I bought body suits on sale at Myer and gave them one each

Small musical instruments are great for younger kids too - castanets, mini maracas, bells, etc.

There are some great sites online that sell party favours