If you’re self-employed, business travel outside your home town is deductible. If you’re trip does not involve an overnight stay, you may deduct your travel expenses—mileage or airfare—but you cannot deduct meals as you can if you’re staying overnight. And you can splash out—travel first class and stay in a five-star hotel if you can afford it; you don’t have to stay in a mid-priced hotel to make your hotel stay a deductible expense. But remember, you’re still going to pay for the bulk of that trip out of your pocket.
Keep careful track of your expenses and note the business purpose of a meal if you’re hosting someone else.
If you travel away from your home for the express purpose of looking for a new job, that’s deductible, too. Keep a record of interviews and other proof of intent. Professional publications or books are also deductible. So are business gifts up to $25.
If you’re in doubt, ask an accountant; I don’t accept collect calls from guys getting audited!