I'm sure this has been addressed somewhere, but upon first inspection I could not find the answer. Anyway, does anyone know how to make audio sound like it's coming through a phone? (You know that muffled kind of sound). I use sony soundforge by the way. Any help is greatly appreciated.

Any sound coming through a small speaker, like a telephone, is going to sound tinny and have a lowcut (also called a highpass) filter applied to it. It's also not going to have crystal-clear high frequencies, so apply a highcut (also called a lowpass) to it around 10k. Play around with the cutoff points, but the general gist should be that you're only letting the mids pass through. You should also add some compression to it.

Excellent, thanks for the help.

Easier and more convincing: play the recording into a cell phone and record it at the other end from a speaker phone.

Compression and equalizing.

Use a high pass filter, boost the mids in the EQ, cut everthing else.