Dividend reinvestment plans, also called DRIPs, let you purchase shares of stock directly from the company, without a broker, by reinvesting your dividends. Many plans let you buy additional shares by making a cash payment.

Some plans charge transaction or account fees, others don’t. Some sell stock at a discount from the market price, others don’t. Some let you acquire your first share of stock from the company; others make you acquire at least one certificate through a broker, who is likely to charge a fee for issuing a paper certificate in addition to a commission.

These plans let small investors gradually accumulate stock on the cheap and put their dividends to work rather than fritter them away.

The downsides: You usually don’t get to choose precisely when or at what price you buy or sell shares. And unless you participate in a DRIP through an individual retirement account, tracking your cost basis and holding period for tax purposes can get extremely complicated, especially if you are buying whole and fractional shares over a long period of time.

To offer a DRIP, a company must pay a dividend; many don’t. To find out if a company offers one, check its Web site under investor relations. Unfortunately, there’s is free, comprehensive list of dividend reinvestment plans on the Web. Sharebuilder.com is a brokerage firm that caters to DRIP investors.