Money Matters
Gambian currency, the Dalasi (GMD, D), is freely convertible but is not available outside of the country. Coins comprise of 50 Bututs and 1 Dalasi. Notes comprise of 5, 10, 25, 50, and 100 Dalasis.
The Gambia is a cash economy and travellers should carry sufficient currency to cover the expenses of a planned visit. Bring a mixture of cash, traveller's cheques (though these can be difficult to cash), a credit card (accepted only at major hotels and a few other places), and a bank/debit card with you (Canadian bank cards, for example, do work in the local bank machines and your chequing account at home will be your "current" account at the machines). 
US dollars, pounds sterling, and euros can be exchanged the easiest. Keep in mind that the exchange rate in the hotels is usually more expensive than at the exchange booths (located mainly in the tourist strip of Senegambia).
Bank machines are available at some of the banks in the Kombos area and are usually open 24hrs, though often the machine may be shut down due to technical difficulties or lack of actual cash.
The maximum that you can take in cash from either a credit card or a bank card is 2000D per transaction, with an 3 transaction limit (usualy).
The Gambia is relatively cheap compared to countries in Europe and North America, however, not as cheap as you may be expecting, especially in the tourist areas. On a small budget you can probably get away with spending less than US$20/day/pp (includes food, transport, and some entertainment, per person, not including accommodations).
For an average budget it will cost about US$40/day/pp, and if you want complete comfort it will cost about US$80/day/pp (including some organized trips as well).
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