Harmonica/Recording

As of now, there are no detail Wikibooks on home recording, but I will just go with what I have:

With the advent of computers, it's entirely possible to do multitrack recording right at the comfort of the home, with only additional equipment of a mic and a good software then can cost less than $20.

Microphone
If you have a bullet mic, cool — but you don't really need something that expensive. The one that I used is a simple uni-directional moving coil (dynamic) mic, with the impedance of 600 ohm. The key point here is mainly the direction of the mic: it's uni-directional, which captures only the sound of the harmonica.

Lapel mic is not a bad choice, but do watch out that it's omnidirectional, making it suspectible to outside noise. Also, it's common for it to use poor quality wiring, making it suspectible to statics — and your normal home computer (not one designed specifically for recording) generally generates lots of statics.

Software
The few good software that can be used are as follows: I would recommend Audacity if possible. Yes, I do know that Audacity is not perfect, and many commercial software ARE better. However, there are a few reasons why I would recommend Audacity: Get version 1.3.2b. for the most part, it is stable enough. The user manual for Audacity is located at here.
 * DK Hit Kit ($15 CDN). Cheap, comes with a lite version of emagic Logic. Can edit 8 audio track and 16 midi track. Comes with a good quality mic too, easily the price of the Hit Kit itself. For Win and OS X.
 * Audacity: Released under the GNU GPL (meaning free and libre). As many audio tracks as your computer can handle, and have lots of effects and plugin. For Windows, OS X, Linux, BSD, and Solaris.
 * Ardour: Released under the GNU GPL (meaning free and libre). 64 audio tracks and 16 MIDI tracks available. For Linux and OS X
 * Dyne:bolic Multimedia oriented LiveCD Linux that includes Audacity, Ardour, drum machine, and audio streaming engine, as well as tools to edit videos. Version 1.4.1 Can run on any 586+ PC (with CD reader) with 64mb RAM and X-Box; version 2.2 can run on most computer made within last 2 years.
 * 1) It's free and libre, and suitable for home recording... and semi-professional graded too if needed
 * 2) It can be used for any operating system, not just Windows or Linux or Mac. This allow any computers that have Audacity program to open Audacity project files, without the need for a Live CD (which is useless on a Mac, as far as i know).

Recording tips, and other ideas

 * Holding the mic will introduce handling noise.
 * Since Audacity Project file retain information such as separate track, it allows collaborations of musicians who may not have met; instead of merely sending numerous dissatisfactory setted audio files that cannot be edited properly, musicians can send the project and associated audio files, and can listen and decide what to keep, and etc.
 * A further extension would be "chain-letter jamming", where, one musician record a track and pass it down, and keep going among the circle.