I use the little key (looks like a paperclip) that came with the iPhone to do it. Basically, all you have to do is put the end of the key (or paperclip) into the little hole and push firmly. The SIM door should pop out a little letting you pull it out with your fingers. Facebook: http://www.facebook.com/phonebuff.
Currency of Srilanka. Currency of Sri Lanka is Sri Lankan Rupee. One Sri Lankan Rupee consists of 100 cents. Coins come in the denomination 5, 10, 25 and 50 cents and Rs. 1, 2, 5 and 10. The higher value denominations are found as notes, namely Rs.10, 20, 50, 100, 200, 500 and 1000.
Do not forget to change your money back before leaving the country because you are not allowed to export many rupees (maximum of Rs 5,000) nor do many foreign banks exchange the Sri Lankan currency. It seems strange but you are not allowed to bring large amounts of rupees into Sri Lanka.