You can buy a Square reader in places like the Apple Store, BestBuy, RadioShack, etc., for about $10. You'll have to pay tax, but the box includes a $10 credit for your account.
You can also request they send you one for free.
Works good. Have used it a few times and have had no issues.
Square is 2.75% flat.
Intuit Swipe appears to be 2.7%, but 3.7% if you manually enter it (type in the card number instead of swiping). They do have a "high volume" account that has a lower percentage rate, but a monthly fee.