the r-09 from edirol/roland is super sweet.. i got mine a couple weeks ago and i love it. it is a bit more expensive than the m-audio microtrack but it is way worth it.
the built in mic is amazing and i love the user interface. you should defiantly check it out if you are really serious about field recording.
or if you have a newer ipod you can get this really good mic input thing for it. a friend of mine has one and it makes great recordings through its detachable mic or its line in.