Finding the lowest airfare may sometimesseem impossible, but there are acouple of Internet sites that can help.Smarterliving.com will e-mail you aweekly newsletter that keeps track ofwhich major carriers are offering airfarebargains, from advance purchases to last-minuteweekend deals. If you're theimpulsive type, those weekend bargains,which hit your e-mail inbox everyWednesday, can save you some seriousmoney. On a recent weekend, you couldhave bought a round-trip ticket fromNew York to San Francisco for $238; for$148, you could have flown to Dallasand back. Other travel sites, like Travelocity(www.travelocity.com) and Expedia(www.expedia.com) will put you ontheir e-mailing list for bargain alerts. AtTravelocity, you can ask to be notifiedwhenever a ticket between 2 cities youspecify goes on sale.