I don't know how popular a technique this has become, but I've been using portable recorders + lavs instead of RF wireless mics for over a year now. I use a Sony ICD-SX712u portable recorder and a lav mic that came with my Sennheiser G3 kit.
I just plug the lav mic into the recorder, mic the talent as usual, and sync it up in post with FCP X.
This eliminates the hassle and expense of a full wireless system, you don't have to deal with radio interference, and you have unlimited audio channels. The only main drawback is the inability to monitor sound as it's being recorded. But so far I've had really good results just by carefully mic'ing people beforehand.
I've done a blog post which details exactly how to set up and use this system:
http://rungunshoot.com/diy-wireless-mic-lav-mic-portable-recorder-diy-belt-clip-holster/
I just plug the lav mic into the recorder, mic the talent as usual, and sync it up in post with FCP X.
This eliminates the hassle and expense of a full wireless system, you don't have to deal with radio interference, and you have unlimited audio channels. The only main drawback is the inability to monitor sound as it's being recorded. But so far I've had really good results just by carefully mic'ing people beforehand.
I've done a blog post which details exactly how to set up and use this system:
http://rungunshoot.com/diy-wireless-mic-lav-mic-portable-recorder-diy-belt-clip-holster/