Styrofoam buckets are a start. The key is to make sure the bucket is bone dry when you put water in it, and use another vessel to dip the water into your bucket, don't submerge your bucket in the water to fill it. You'll notice that the bait shops always scoop water into your bucket, or fill your bucket with a hose. I don't know why, but the styrofoam buckets keep bait alive for a longer time if the outside of the bucket is dry, and the inside was dry before it was filled.
There are lots of add-on livewell kits available, ranging from a simple battery powered aquarium style aerator. to replacement livewell kits with alligator clip leads to hook to a 12 volt battery. There are also bait buckets available with battery powered air pumps as part of the kit, or are actually mounted to the bucket. There's always the old 2 part buckets where you hang the floating insert in the lake and retrieve a few minnow on an as needed basis.
