TeXnical notes
Sometimes I find a solution to a TeXnical problem, and I think everybody should know about it. Some of these things are totally obvious, but (as far as I know) non-standard.
BibTeX without a separate .bib file
How to draw the Fox-Artin wild arc with pstricks
tex pdf (pdf contains only the resulting image)
Placing labels on arrows in XY-pic
(I learned this trick from Aaron Lauda; I haven't seen it documented anywhere)
\xymatrix{asdfasdf \ar[r]^{f} & a }
produces the label "f" in a stupid place, half-way between the centers of the two entries, instead of where you'd like it to be, half-way along the arrow. One way to handle this is to do something like
\ar[r]^(.7){f}
but that is fairly unsatisfying because you have to calibrate the (.7) by eye. There is another way, which is to use
\ar[r]^-{f}
which will automatically place the label "f" half-way along the arrow. If you want the label .7 of the way along the arrow, you can do
\ar[r]^-(.7){f}