Here are two phrases for tech-savvy businesses to add to their lexicon: domain name "drop-catching" and "getting in on the drop."

Have you ever wanted to acquire a domain name someone else has registered?

You do not own domain names perpetually. You register them for a period of years. If you don't renew the registration, the domain name becomes available for registration by others.

There are many reasons why you might want to corral domain names that are already registered.

Sometimes you may want to obtain an already-registered domain name because it matches the name of a new business, product or service you'd like to launch. Or the desired domain name might be a shorter, more memorable domain name for your current business. Some people buy domain names for resale or to put up pay-per-click advertising.

Also, in my trademark practice, clients often want to acquire registered domain names that are highly similar to their trademarks. Indeed, before you register, use, buy or sell any domain name for any commercial purpose, you should make certain your doing so will not infringe on someone else's trademark.

     Unfortunately, it's nearly impossible to get a domain name by waiting for its registration expiration and then registering it just like you would with a never-taken domain name. To be successful, you'll almost certainly have to use a "drop-catching" service and pay more than you would for a normal domain name registration.

     Specifically, you face two hurdles — timing and professional competition.

As for timing, domain names don't become available on their listed expiration dates, which you can look up on a domain name registrar's website (e.g., GoDaddy.com) using the "whois" function.

Once the expiration date arrives, the domain name goes in grace periods of about 70 cumulative days during which the current registrant still can renew.

After that, the domain name is put in lockdown for five days and is placed on a "pending delete" list. The domain name cannot be transferred during that time.

Then the domain name is "dropped" back into the pool of domain names available for registration by anyone. The drop occurs somewhere in a three-hour window. It's a jump ball. The art of trying to register a domain name at that time is called "drop-catching." Competitors are trying to "get in on the drop."

If the domain name is desirable, you have almost zero chance of beating the pros at the drop. Thus, the best approach is to subscribe to a drop-catching service that will watch the drop and snag the domain name for you.

Various online companies offer drop-catching services. They are competing to win the drop, so generally no single company can assure victory. You can use one company and hope it wins, or you can use multiple companies to increase your chances.

Currently, it appears that the biggest players in drop-catching are Pool.com, Snapnames and NameJet. With each, you give your credit card information and are charged if and when it successfully obtains the domain name for you. Expect to pay about $60 per domain name if no one else tries to register it using the same drop-catching company.

       GoDaddy.com offers a cheaper service, but you have to pay up front.

If others also try to buy at the drop through the same drop-catching company, the domain name probably will be put up at auction, so you'll have to bid against faceless competitors.

Of course, the better strategy is to register desirable domain names while they are still available. You'll pay less — about $10 a year — and spend less time. Business strategy for pre-emptive domain name registration is a topic for another day.