A London vacation for $900 -- airfare and hotel? Cancun for $500? I got an email alert this morning about big after-holiday airfare sales -- and as a frequent traveler who is often frustrated by the price of airline tickets, I jumped at the chance to research some sweet mid-winter vacations.

Via Expedia, if you book now and travel by mid-March, you can snag very cheap round-trip tickets out of LAX for places like London ($502), Vail ($277), Honolulu ($349), even Tokyo ($791).

Pair that with a hotel package and you can get yourself a three-night stay in Cancun, airfare and hotel included, for prices as low as $500 per person. Sounds like a perfect winter -- or Valentine's Day -- trip to me.

You can also get to New York City from Burbank on JetBlue for about $150 if you travel before mid-February.

Finally, a quick search for all Los Angeles airports on Airfare Watchdog revealed cheap "this-weekend-only" fares as well as unadvertised round-trip bookings through March and April to places like New Orleans ($198), San Jose ($98), or Las Vegas ($98). Or if you're feeling more internationally-minded, why not try for Shanghai ($746), Barcelona ($473), or Berlin ($383, if you leave on a Tuesday)?

Be sure to read the fine print carefully on all of these deals -- many of them depend on Monday-Thursday departures, or are only good for travel during certain dates. But if you're looking for a long-weekend trip this winter, there's a ton of deals available for the careful airfare shopper.