I use LaTeX for nearly all of my document preparation. Letters, reports, you name it. Because I'm always finding new uses for it, I find myself frequently downloading packages from CTAN (the Comprehensive TeX Archive Network).

I find it a hassle to copy a package's URL from my desktop (where I searched for it) to my netbook (where I want to download it). To solve this problem, I've written a little shell function that downloads a package for me. If you want to use it, just stick it in $HOME/.zshrc if you use zsh, $HOME/.bashrc if you use bash, etc.

ctand() {
    wget http://mirror.ctan.org/macros/latex/contrib/$1.zip && unzip $1.zip

To download, say, the program package, you'll want to run ctand program

Note: You'll need to run source $HOME/.zshrc or source $HOME/.bashrc after editing either to be able to use it. Or you can open a new terminal and use it there.