I'd highly recommend taking advantage of my tips for free trips to Vegas or Europe. However, if you must spend money on a vacation I do recommend considering a cruise. You can find great deals on cruises and considering it includes food 24x7, travel between destinations and lodging it can end up being cheaper then a "free" trip where your paying for food.
Now how do you get there free? Thats tough. Marriott rewards offers a redemption option of 145,000 pts for $1k towards a cruise. Its not a bad deal, but unless your a business traveler spending lots of nights in Marriott its tough to get that many pts. You can use money from Ebates and credit cards like Discover that give you cash back. However, usually u can find a cheap deal to do a cruise, b/c they make most of their money on booze and excursions. So here are the tips you need to keep those costs down:
1. Don't book excursions through the Cruise. You can usually do them completely on your own for 1/5 of the price or through a private company for 1/2 the price. The Cruise Critic Message Board is a great place to research any port you might be going to and find ways to do it on your own. Also they have a roll call section which you should be able to find your actual cruise and meet people that will be on the same cruise as you. Then you can make arrangements with people on your same cruise to split different private tours.
2. Bring your own Alcohol. If you do a princess cruise, must allow you to bring 1 bottle of wine per person. Then its my experience you can continue to bring 1 bottle per person at each port. Actually its my experience you can bring a lot more, but the policy is 1 bottle. Just make sure to pack a bottle opener or buy @ port. The bottles will easily fit in your fridge and just call room service for wine glasses. You can then drink in room and/or bring to dinner anywhere on deck and they will assume you got it at the bar.
3. Utilize Casino as means to get more frequent flyer points. Some cruise casinos allow you to purchase chips with your credit card without charging you a cash advance fee. In my experience I have been able to do this at NCL and through Princess Cruises Poker table. You can charge the money, get the chips, play a minimum amount and cash in the rest for cash. Problem is then you have a bunch of cash you need to carry around and then deposit in a bank. Its not always worth the trouble for just say 10k worth of points, but for example if you had signed up for the SouthWest credit card listed below - you could do this just to get your 5k spend and your $500 gift card.
Enjoy these great tips. Keep checking back for more...