if I buy the iphone 3g from france , can I use it in egypt with my vodafone simcard

Ya sure you can use iphone 3g with vodafone sim only if it is unlocked one else if the iphone 3g is locked to some other network provider in other country then it wont accept any other GSM sim until you unlock it ..You can easily unlock the iphone 3g through online providers like MobileUnlockSolutions.com here they are rendering remote unlocking service to unlock all model iphone from network provider .You first check that whether the service is available for your country and network provider .If yes then pay for it and unlock the iphone 3g then freely use it with any GSM sim ....