Last year, we looked at an ash vacuum that can make cleaning up the fireplace a little easier. If you don't have a couple hundred bucks to spend on a dedicated fireplace vacuum right now, then here's another (cheaper) cleanup solution:
The fireplace ash tray sits on the floor of your firebox. When you're burning a fire, the ashes fall through your grate and onto the tray. Once the fire is out and the grate is cool, all you have to do is slide out the tray and dump the ashes. The handy tool eliminates the need for a shovel, vacuum, broom, etc., and it's expandable to fit different sized fireplaces.
$30 over at the Improvements Catalog.