Sports fans often are avid — if not rabid — collectors of memorabilia celebrating their favorite teams and players. Millions of these superfans are also online, actively buying and selling sports-related goods. They can be found on any of the major sites, such as eBay and Yahoo! but they also surge into their favorite niche auction sites much the same way they push into a stadium on the day of a big game — pumped up and ready to play. Here are some of the leading sports online auction sites.

Heritage Sports Collectibles

Dallas-based Heritage Sports Collectibles (www.heritagesportscollect-ibles.com) plays both sides of the auction field. It stages live auctions of rare sports cards and memorabilia at major sports conventions, and it hosts its monthly Amazing Sports Auctions online. Membership is required to bid. In late 2005, its membership totaled about 15,000. Heritage Sports Collectibles is a subsidiary of Heritage Galleries & Auctioneers, which bills itself as “the world's largest collectibles auctioneer.”

Lelands

Lelands.com modestly claims to be “the largest and most respected Sports Auction House in the world.” It has handled some of America's most famous — and, some would say, infamous — sports memorabilia transactions. One of these was the sale of major-league baseball's famous “Mookie Ball” to actor Charlie Sheen for more than $93,000. This was a baseball hit between the legs of a Boston Red Sox first baseman during the 1986 World Series. Many fans believe the error caused the New York Mets to win the World Series and continue the Red Sox's long-running curse of not winning the Series. (The 2004 Red Sox finally ended the curse that had lingered since 1918.)

Based in Seaford, New York, Lelands.com also handles Americana memorabilia and uses the five-minute rule in its online auctions. Bidding can continue past the scheduled closing time until there are no more bids during a five-minute period. Winning bidders pay a 17.5 percent premium, as well as all shipping and handling costs.

To register to bid at Lelands, you must be able to list at least one reference, such as a valid eBay account with a positive feedback score or a verifiable account with at least one other auction house.

bid4sport

It seems as if every major sports auction site calls itself “number one” in some category. In the case of Great Britain's bid4sport.com, the claim is “the world's number 1 site for 100% authentic, autographed memorabilia.” Only registered members can receive information about upcoming online auctions. However, bids can be placed from anywhere in the world. Interestingly, bids can also be placed by telephone if you can't get to a computer on a day when an auction ends. A representative will place the bid for you. However, the telephone bidding service must be scheduled at least twenty-four hours in advance of the auction's end.

NHL.com Auction Network

Hockey fans who like memorabilia and hockey equipment can bid on everything from pro stars' signed jerseys to hockey sticks, pucks, and face masks at auctions.nhl.com, the National Hockey League's online auction site. Other items include posters, autographed caps, and Olympic gold coins.