Products like the Zoom H2, H4 and H4n are hotly debated; some think that they're a great option, others are not quite so sure. The general consensus is that the mic preamps of these Zoom products are rather noisy, so a quality mixer like the Sound Devices MixPre ($650) or even the MP-1 ($300) or MM-1 ($350) should be used and the output of the mixer sent to the line inputs of the Zoom recorder being used. Another strike against the Zoom products is that they really eat batteries; you could easily go through half a dozen batteries or more every day you shoot. Even at $0.40 each that's $2.40 a day, $24.00 for ten days of shooting, $240.00 over 100 days of shooting. Would you rather spend over $200 on batteries or gear? A third point against them is that they are rather flimsy; drop it and it makes a nice paperweight.
Another low budget option could be the juicedLink CX231 or the Beachtek DXA-6A. Both supply phantom power, have two channels, mount underneath the camera, are relatively economical with batteries (9V), have passable preamps and are made specifically for use with cameras that have 1/8" mini-pin audio inputs. The problem with them is that they are a one-trick-pony; if you upgrade to a prosumer camera that has XLR mic and RCA or 1/4" line inputs the unit is no longer useful.
The ultimate point is to bypass low quality mic preamps which add hiss and possibly other artifacts to the audio. If you want to get into the $600 to $1,000 range your options - and the quality - increases markedly. The Fostex FR-2 LE, Marantz PMD661, Nagra ARES-ML, Tascam HD-P2 and Edirol/Roland R-44 are all very viable options. All have relatively quiet preamps, are well built and can be used as building blocks for a larger, more flexible system; you could later on add a mixer like the MixPre or the 302.
By the way, having the mike on a stand or on the camera and using a separate recording device will not produce a significant improvement in the sound, but your sound will markedly improve if you boom properly.