Here's my situation:
I accept credit cards (Amex) over my Android phone
About 1 or 2 transactions per month
Each transaction is generally between $1,000 - $7,000
Square is nice & easy--virtually no setup--but the fees are a bit high, 3.5% per phone transaction.
I recently found Dwolla.com, who offers a transaction cost of 25 cents (!) per transaction--which would save me a bunch of money. However, I've seen mixed reviews of Dwolla online, and wanted to know if anyone else has used it and what their experience has been.