I have started designing a guitar FX pedal, which has distortion and modulation (can't say too much - commercially sensitive). When I finish the prototype I'll get some feedback (oh, very droll) from a few guitarists.

1. Overdub rhythm parts (drums or bass etc)
2. Get that phasey sound on the cymbals
3. Compress the whole mix heavily
This will pretty much over-ride any good decisions you have made for balance and EQ.

I have been shopping for a digital still camera, and after looking into it I bought a Fuji Finepix S1800. It has 18x optical zoom (which is equivalent to a 500mm lens), weighs about 400gm, and has 12Mpixel resolution. But wait, there is more...no less than 10 modes; including full manual, tracking autofocus, it can even seam shots together to make a panorama. Here's the best bit  - it cost only $NZ350. Isn't technology great.

Imagine you want to recreate an acoustical environment that simulates outdoors. Outside (and away from any buildings, hills etc) there is nearly no reverberation. To recreate the same sounding space indoors we need to have an anechoic chamber, which will absorb almost all the sound. The strange thing is that this type of room sounds very unnatural to us, whereas we are completely comfortable with sound outdoors.

Do you gate during recording or wait until mixdown?
I prefer to do it at the tracking session. This habit started before plugins when a rack unit (gate, compressor, reverb, EQ etc) needed to be used twice ie at tracking and again at mixdown. These days with plugins I am unlikely to run short of signal processors but here are three other reasons why I think it is better to gate while recording - 
1) it makes me think hard about the exact sound required for the song
2) it forces me to control the session properly. By this I mean not rushing, and ensuring that the musicians are in a recording mindset rather than a live performance one
3) there is a payoff at mixdown time. Instead of starting by fixing problems I can get straight into
making a good thing sound better - a much nicer way to be mixing.

Mastering has become the new buzzword in audio engineering, just as the word digital used to have seemingly magical properties.
Mastering should be (and always used to be) providing small changes to a stereo mix to ensure that the album is consistent with other  albums in the same genre. Hence the role of the Mastering Engineer as a specialised audio professional: he / she is the person who a) has golden ears, b) has an excellent listening environment (room and speakers), and c) has vast experience of what a mix should sound like due to listening to many similar mixes from multiple studios.
Fast forward to today and every wanna-be pup engineer with ProTools LE wants to master his own recording. For an average band recording this will entail multiband compression, limiting, equalisation, and adding dither as the mix is bounced from 24 bit to 16 bit for CD.
The usual result is to produce a final mix that is over-compressed (and harsh sounding), and as the level rarely leaves 0dBFS dithering becomes pointless.
Dave Moulton has a good article on mastering here.