Hey, here's an idea. Run the Microphone into your portable audio recorder, and then run the headphone out port into your camera mic input. If it sounds good in the headphones, it should sound good running into the camera. Well before you tackle that idea, just know that headphone outputs aren't all the same and run pretty hot. Some portable audio recorders have a dedicated 'Line Out' so you'll be safe, but not the Zoom H4n or Zoom H1. You can easily damage the mic input on your camera if you're not careful.
So above is the cable from Sescom. This isn't something new, and most of you might have already run into this product. This particular one I have is for the Zoom H4n, but i'm showing it with the Zoom H1 (didn't have H4n with me). It's a Sescom Line2Mic attenuator cable that drops the headphone out from the Zoom by -25db making it safe to use directly into your camera's Mic input. There's different cables with different levels of attenuation provided for different recorders. Don't think this will save your AGC enabled cameras, that's not what it's there for. This cable is for the Canon 60D and 5D Mark II that control manual audio. (Or try it on the T2i with Magic Lantern).
So why do it this way? Well for starters, the amps on the Zoom recorders will help you adjust levels and sensitivity. If you're using the H4n, it gives you a way to connect XLR type microphones. Is the audio just as good as what's recorded? Not really, but you'll be surprised on how well it does sound. I'm not going to run through a bunch of tests today, a bit swamped, but if you're curious you can find lots of tests already at Vimeo.com. Or for those of you who have your video links, throw them in the comments.