Yes, these are called DRIPs which stand for Dividend Reinvestment something...
There are only a few hundred companies that offer this plan, without you having to go through a stockbroker. There are basically two ways to join these plans: 1) sign up directly with the company. You can do this online with many - just fill out their form and send in the deposit. You'll have to send in a hefty deposit, but can make small investments later on (as little as $25 a month for some companies. 2) Some companies require you to own one stock already before you can begin the DRIP program. This means that you need a broker to buy that initial stock, and then you can manage your account with them by yourself.

Beware you do have to pay service fees with most companies, but it is less than broker's fees.

Browse some websites on this subject - I even found a book on them at my local library.