If you are shooting with a DSLR you already know about the sound issue. The DSLRs’ built-in microphones are not very good, you could use an external microphone on the T2i but the AGC ( “Automatic gain control”) remain a problem…
So one of the solution is to use an external sound device like the zoom h4n and synchronize sound/video in post-production. I just got a Zoom H4n for $240 on ebay ( refurbished, new it goes for $299) and I was blown away by the audio quality out of the box ! The built-in microphones are actually very very good. The H4n also allows you to plug 2 external microphones via XLR or Jack inputs (phantom-powered), and record up to 4 channels, resolution ranges from a maximum of 24-bit/96kHz. All that for less than $300 !
Today was another gorgeous day in the bay area so I went to Baker Beach this morning to try my H4n outside with my windscreen from redhead ( for $34) And It worked great:
Recording with the redhead windscreen:
Recording without the redhead windscreen:
Here is another exemple from redhead: