I will be visiting San Ignacio and Caye Caulker next month, are cards widely accepted in these areas? I'll have cash as well, just wondering if I can count on credit for tours/restaurants/transportation.

Most take credit cards, in some cases there is a surcharge due to the ridiculous bank charges but you'll do fine. As far as transport goes the airlines take cards, not sure about water taxi, and the bus lines and taxis don't.

paid for our water taxi tickets w/ Visa once (no AMEX) and w/ travellers checks a coupla times

The problem with credit cards...is the new charge that the credit card companies are charging. It is about 3% on foreign exchange. I'd take as much cash as you feel comfortable carrying.

Most places accept the cards....I don't want to pay the extra fee.

I've heard that some Credit Unions are not charging the fee....

I've always thought using my credit card is the best, but I decided to avoid using it.

First, the additional exchange fees. Discover has none, but it is not widely accepted. Second, the crappy exchange rate. I found out that my bank's fees for buying traveller's cheques will come out cheaper than that of what I'll be losing from the credit card exchange rates. Note that the traveller's cheque cards work like a credit card with a crappy exchange rate. They may have additional fees, too.

I finally decided to bring paper travellers cheques and cash and use my credit cards as just a backup.

Sounds like the high fees will be a nice deterrent for going too crazy on the card while on vacation. It's good to know that it is accepted at most places just in case.