Some nice projects.

[tripp]

http://www.nuxie1.com/guides/hackaday-competition-entry.html

look under guides for more.

/Tripp

[Math]

Not all those projects are that nice !

For example :

http://nuxie1.com/guides/function-generator.html

It's a good project but everyone who wants to build a function generator better doesn't use those XR2206 IC's.
Those things are low budget generators. Here in belgium one of those costs like 4 euro.
But if you use a MAX038 you have to pay like 40 euro.

But money = quality. I wouldn't recommend the XR2206 if you want to make some good ..