If the price of an Eye-Fi card makes you baulk, there's another option: microSD card adapters with built-in Wi-Fi (such as this one from Monoprice). These enable a microSD card to work in your camera's SD card slot, and also give you internet access on the go.
They create a specific Wi-Fi network that you'll be able to see on other devices such as your smartphone, tablet or laptop, in the same way you would your Wi-Fi network at home. Connect to the network from those devices and you can view any pictures on the card in a browser, and download and share them.
They're not as flexible as Eye-Fi cards – you can't have automatic photo upload, and you'll need a microSD card in order for them to work – but you can pick one up for next to nothing.
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