There are a few software options and you can get decent results using this method (I dont have a wedge at present - so that is how I image. See my website link in my sig)
Check out the following:
http://www.astronomie.be/registax/
http://deepskystacker.free.fr/english/index.html
http://www.iceinspace.com.au/forum/s...ead.php?t=6489
http://stellar-magic.com/download.html
For the spectacular deep sky images you see on this forum and around the web - you will eventually need a wedge. The stacking option can still be used in conjunction with a wedge - but obviously the wedge gives you the option of longer exposure times.