There are a lot of bid management tools you can use, however most of these big management tools want a percentage of your total monthly spending budget. Most PPC management companies charge 10% to run and manage the account, seems unfair but thats how the cookie crumbles. When i was at the SMX show last week there were a few booths there offering PPC management tools. the only one i seem to remember is a program from Marin software. Its fully integrated with Google Yahoo and MSN.