My family spilled a whole glass of wine over the keyboard of their precious MacBook Air, it went completely dead and I didn't have the tools to open it so they had to send it in at the store for repair. They were told repairing it would cost well over $1000 with no warranty against later problems, so they decided to buy a new one instead, leaving me with trying to rescue the data from a dead drunk laptop.
After taking the Air apart completely and inspecting the damage, It didn't look all that bad besides the competely ruined keyboard. A google search for water damaged macbook airs returned a page explaining that there are two small test points on the logic board marked PWRBTN. If the logic board works, it should power on when you bridge those test points. I tried it, and it worked, booting into OSX! The machine was incredibly slow, but again googling for other water damaged MacBooks it seems that the SMC throttles down the CPU as much as it can if one or more temperature sensors are malfunctioning. Since the trackpad and keyboard was disconnected I hoped the sensor on that board was the reason. There is a way to unload the kernel extension and make the machine faster again, which I did before doing a time machine backup with an external keyboard and a big USB drive.
I ordered the cheapest new MBA top case I could find on eBay.
(It looks like you can replace JUST the keyboard if you're brave enough to break all the keyboard rivets and glue them back on afterwards, but I decided to spend a little more to avoid the risk of tiny loose rivets shorting out the logic board)
Following the iFixit guide was a snap, and after cleaning out most of the sticky wine residue, the laptop is good as new!
Make sure you keep track of which screw goes where! Place them on a strip of sticky tape in the order you removed them, or use a sorting box with lots of compartments. I made a small dent in my shiny new top case by using a screw that was too long at the wrong place. Don't trust the guide blindly for screw lengths like I did!