I recently picked up a 4GB Eye-Fi memory card that lets you upload images straight from Camera to on-line resources such as Facebook and Flickr and also to folders on computers connected.
The installation was a little more painful than I had hoped... The card kept being ejected whilst the software was copying across and even ejected itself half-way through a firmware update... which was not ideal.
Eye-Fi are planning to launch connectivity to mobile phones and iPads later this year which will add even more useful functionality.
I'll write up a full review when I have had a chance to use the card for a while in my Panasonic LX5