This page contains some solutions to problems that I couldn't find easily on the web.

Happy Hacking Keyboard (hhkb)

Using Umlauts with the Happy Hacking Keyboard

With xkeycaps: Launch xkeycaps, Select the Keyboard (PC / Happy Hacking Keyboard), Choose one of the unused keys (e.g. key 81) and right-click on it. Choose "Edit KeySyms of Key" and then map KeySym 1 to Keyboard / Multi_key. Disable auto repeat. Click "OK". Click "Write Output".
Now press that key together with the shift key and the "-Key followed by an 'a' to produce an ä.
BTW: You can buy HHKBs from here (Netherlands). That's where I got my two from.

cygwin

Switching off the annoying system beep

File: ~/.inputrc

    set bell-style none
  

Switching off the annoying beep in vim

    :set vb
  

LaTeX

Creating PDF's

For a long time I had the problem that PDF's created with LaTeX (dvipdf) looked really ugly. The fonts were always kinda fuzzy. After trying several different distillers and other suggested solutions which all came with some major down-points, I found that using the packages txfonts and pxfonts was the best solution.

Mozilla

Installing a spell checker

There is a spell checker for Mozilla. spellchecker.mozdev.org.

Merging PS Files

cat file1.ps file2.ps >all.ps
or
cat file1.ps >all.ps
echo "false 0 startjob pop" >>all.ps
cat file2.ps >>all.ps