The Rode Video Mic is a very good low cost video mic that produces a good sound quality for the price.
The mic is super cardioid and does pick up nicely - but its got a wider pick up angle than some hyper cardioid mics I've used.
The windsock is totally essential if you are recording outside as the standard one that comes on the mic doesn't do the job well enough on its own.
A decent 9V battery lasts for ages - if you remember to switch it off when you finish recording.
The mounting system is kind of delicate and feels floppy on top of the camera, but mine hasn't fallen off yet!
And you do get spare bits in the box if one of the rubber mounts breaks.
The mic fits a standard camera shoe and plugs into your camera via a minijack (3.5mm) - the lead isn't very long though.
One down point is that I did find that after couple of months some battery humm (low level, very high pitched tone) crept into the background - but it wasn't noticeable on the final track.
Overall the sound if much better than an integral mic, its quite robust and its the best mic as I've found for this price bracket.