The adage "what goes up must come down" doesn't apply to ever-rising airfares. That's why it's so important for budget travelers to follow the deals rather than have a destination set in stone.

(Note: All European airfares mentioned here are inclusive of $210 in fuel surcharges, but exclusive of extra taxes and fees.)

For instance, if you're set on traveling to Paris this spring, round-trip rates are $1,053. If you're longing to return to Rome, expect to pay $1,066. Instead, visit Budapest, Hungary, with Delta for $636 round trip, or Munich, Germany, for $731. Both rates are based on midweek travel March 25 to May 15. Buy tickets through March 16.

A deal available for purchase through Friday and valid March 10 to April 30 is a round-trip rate of $832 on Delta to Prague, Czech Republic. Trips are permitted any day, based on availability.

Through March 16, buy tickets on British Airways or Delta to London at a round-trip rate of $586, valid March 24 to May 25. Trips on Thursdays-Sundays are $30 more each way. Stay at least one weekend or up to one year.

A spot on the Web for great deals on four- and three-star centrally located hotels in London or Paris is www.discountcityhotels.net. The three-star tourist class Central House Hotel near London's Victoria Station is priced from 75 pounds, double (about $146). Numerous last-minute deals and weekend specials are offered by hotels and apartments.

Under the Tuscan sun

What better place to enjoy the sunshine than in the Tuscan region of Italy? Pay $572 round trip on Delta to Pisa, home of the famous leaning tower, about an hour outside Florence. The rate is valid on midweek trips started on or before March 31. Weekend travel days are $20 more each way. You can go as soon as this week because advance notice is not required. Tickets must be purchased by Friday. Delta serves Pisa via connections in Milan or Paris; stopovers not allowed.

Get to Florence from Pisa by rail for about 6 euros or about $9 each way (English version: www.trenitalia.it/en/index.html). Travel time is from an hour to 90 minutes. Venere.com is a top shopping Web site for deals at 8,000 hotels across Italy and Europe.

The great white North

Airfares to Canada have sharply increased. But an Air Canada sale through March 6 brings prices down to affordable levels on trips taken on or before June 14.

Sample one-way prices include $145 to Calgary, Alberta; $150 to Winnipeg, Manitoba; $170 to Halifax, Nova Scotia; $174 to Vancouver, British Columbia; $179 to Toronto; $184 to Quebec City; $186 to Ottawa; $187 to Montreal; $191 to Thunder Bay, Ontario; $210 to Saskatoon, Saskatchewan; and $232 to St. John's, Newfoundland.

Sale rates are valid on Tuesdays, Wednesdays or Saturdays, with other days about $20 more each way. Air Canada, Continental, Northwest and US Airways post no blackout dates on this offer, but other matching carriers such as American, Delta and United restrict these rates on many spring dates. One week advance notice is required.

The charming, pedestrian-friendly ski resort village of Mont Tremblant is about 45 minutes from Montreal, with 94 trails on four mountain faces at varied skill level for boarders or skiers. Tremblant was rated the best ski town in eastern North America by Ski magazine.

Four-night packages from Fresh Tracks include accommodations within a short walk of lifts (or ski-in/ski-out) and transfers from Montreal's airport.

Per-person rates start from $756 through March 15 and from $570 March 22-April 19. Extra pre- or post nights in Montreal or Quebec City can be added. (For more information, click on Mont Tremblant or www.tourismemonttremblant.com)