Depending on how much data you shift around and access from the external storage I would suggest that WiFi connection be your last
choice for an alternative.
In my experience, WiFi is only useful for traffic that's sent in packets that is not time critical, eg. WWW, email, etc. Any large transfers will take a long time at ~300kps which all I ever get on 802.11g at a distance of 700mm.
The most obvious alternative is to modify your behaviour, as a suggestion to help you:
1) Take a length of nylon string.
2) Tie one end to the PSU cable just behind the DC output plug.
3) Tie the other end to the external storage' USB cable just behind the plug for the PC USB port, leaving no more than 1-2cm of slack between the two, ie. just long enough to reach the USB ports closest to the power input on the laptop.
Now when you remove the power to move your laptop you should remember to remove the USB plug or at least wonder, "Who tied string to my power cord?"
Otherwise, if your WiFi router also has network ports then any of the devices I suggested here
Oh yeah, if you really have been dropping your external storage you might want to consider backing it all up to another HDD.