headphone amp

[guitarmonky55]

im looking to build a simple headphone amp, id like something that has some distortion to it too.  i foudn the two at general guitar gadgets, but those dont have built in gain do they?  can anyone suggest a relatively simple headphone amp that will give me some distortion?  something with switchable clean/gain would be nice

[toneman]

put a MOSFET, or JFET, or DoubleD in front of a/the HPamp.

[SirPoonga]

for guitar you just need half of this.
http://www.headwize.com/projects/showfile.php?file=guitar_prj.htm