What: Lets you book a reservation to run with a group of people in Amsterdam if you'll be in town.
Why: Connects runners who want to run while on vacation. The 5-mile route passes Amsterdam's highlights; you also get a drink at the end.
How: Click "booking." It costs 20 euros — about $27 early last week — and the maximum group size is five.
What: The Detroit Metro Airport lost-and-found department
Why: If you lose something at Detroit's Metro Airport, go to this site. You can report your lost object and stay in touch with lost-and-found staff until it's found.
How: Click on "continue" and file a claim. They'll e-mail you a reference number and track the object; they'll notify you if and when it's found. You also can call them at 734-942-3669.
What: If you love theme parks like Cedar Point and King's Island, this site has all the latest news from a consumer's point of view. It covers theme parks as news.
Why: It ranks every ride at every major park. It discusses what's new at parks and what's coming for this summer.
How: Search by specific park. Also see top tips and safety data and contribute your opinion.
What: Networking site for people interested in "slow" travel — not rushing from place to place. Site specializes in Europe but has good info on North America and other world regions, too.
Why: Its best feature is the community forums where members exchange trip reports and practical advice. Traveler accounts are nicely written. Also has reviews of vacation rentals.
How: Click on "community" or "trip reports." And you can search information by region, such as Italy or France.
What: A new family travel deal site by the auction company Luxury Link.
Why: Caters to adventurous families who have a yen for a week in Greece, Hawaii or a suite in Anaheim, Calif.
How: Best feature is the auction section, especially the "closing soon" list. Bid on packages or buy them outright at discounts of about 40 percent-60 percent off.