The built in mic on My Nikon D3100 isnt up to much. apart from it being Mono it picks up noise from lens focusing and general camera handling. The D3100 being Nikons entry level DSLR has no external mic input. TBH, Because of this, for serious projects, i havent really bothered with audio recorded by the D3100 mainly using it as a second camera to the SD700.
I needed an recording device with mic input to accommodate the lavalier this had to be both compact and easy to use. I looked at the Zoom H1 but, mounted to the D3100 it would look clunky and and no doubt be clumsy to operate.
I looked a various digital voice recorders before setting on Sonys icd-ux200.
OK, maximum 192kbps isnt up to the Zooms audio recording capabilities but for now is sufficient for my needs.
A stereo mic input, built in stereo mics and live headphone monitoring knocks the Nikon built in mic for six.
The UX200 will start recording automatically when it receives an audio signal (if enabled) and stop when the signal is cut though I'm not sure if this is going to be as useful or as simple as it sounds.
This thing is so tiny it could easily slip into a pocket and when used with the lavalier mic and auto start function will be totally hands free. However, its more likely i will be use it attached to the hot shoe mount.
watch this space for test results
Sony ICD UX200 2 GB Digital voice recorder - 2 GB flash - Black