Finding crowds at your vacation destination? It's not surprising, since travel in the U.S. was up 7% in the first six months of this year compared to last year, and leisure travel posted the biggest gain, 11%, according to the Travel Industry Assn. of America. . . . In the latest attempt to clean up trash on Mt. Everest, Nepal last week banned bottled drinks from the region. Aluminum cans, which can be crushed and easily carried out, are permitted. Thirty thousand trekkers leave about 200,000 water, beer and other beverage bottles on the slopes each year. . . . Construction delays have postponed the debut of the River Explorer, designed to ply the Mississippi and other waters, from this weekend to Sept. 6. It had already been postponed from July 4. Information: tel. (888) 282-1945.