Moving the Bitcoin folder from AppData Bitcoin's taking a lot of space on my C drive, and I would like to move it to another drive. I've figured out to do it using symbolic links, but the problem is that my Bitcoin client is currently synchronizing with the network. Is there a way to pause it, so I can move the data and then go back to synchronizing?

My C drive's almost running out of space.
You can create a directory junction (as i did to move the BitCoin data folder), or you can specify a different data folder location:

BitCoin-qt.exe -datadir=d:\BitCoinData


Which will be the long-term solution.