Or, perhaps the most expensive: Canon WFT-E7A (not yet available, but coming soon) wireless file transmitter... It can communicate with your laptop, allowing you to change camera settings, use Live View, etc... Plus it will send the images right to your computer, too. Canon claims a 100 meter/328 ft. linked shooting range with it... or 150 meter/492 ft. wireless LAN (image file transmission only). We'll see... they do note these distances are "approximate". But, it's $850 US and not yet available. Hopefully it will be easier to set up than earlier versions of WFTs, but it's said to be future-compatible with planned camera models (all previous WFTs have been largely model specific, so you usually had to upgrade them at the same time that you upgraded cameras).