A lot of people have tossed out some great ideas about U.S. road trips (I love Alaska and Yellowstone/Tetons!), but one nice thing about a long sabbatical is having the time to go somewhere far away if you're interested. My husband and I are on a long trip and have been tracking our expenses pretty closely: excluding our international flights, we averaged about 25-30 dollars per day per person in India and southeast Asia (that would be about $2000 total for two people for 5 weeks). That included eating out for all of our meals, often ordering multiple (sometimes alcoholic) drinks, local transportation including some local flights, renting motorbikes, a private hotel room with ensuite bathroom, going to various attractions, visa fees, etc. We felt like we lived like kings for cheaper than it would have been to stay in the U.S. The international flight can be expensive, but we used airline miles from credit card deals for most of our flights and there are still some decent credit card deals out there to rack up miles. You don't have to spend a lot of money, and it's neat to immerse yourself in some really different cultures.