Rode manufacture some great microphones. This video accompanies the Rode NT1-A Kit recording pack and in it Peter Freedman (company CEO and owner) shows how to knock up an effective and inexpensive vocal booth.
It's fun to get your hands dirty when it's for audio's sake!
The basic technique is to put eyelets in a couple of duvet/doonas, stuffed with craft-store padding, and hang them in hooks in the corner of a room. Extra duvets/doonas can be used to complete the isolation. Simple, inexpensive but effective, just what we like to see! 4,874