A lot of time shell scripts need to do some sort of math. Bash's innability to do floating point arithmatic has lead to some pretty neat workarounds, often times these workarounds are slow. If you need a lot of calculations done with speed, you'll find this snippet useful

This adds your ssh public key to the authorized_keys on a remote server. The key file in the snippet is called id_dsa.pub, yours may have another name but this is standard for DSA encryption.

To learn more about ssh I heartly recommend this: SSH tips and tricks

Recursively removes files or directories with a given name, using find.

I most frequently use it to remove 'CVS' or '.svn' directories from sourcepackages that still have the versioning information in them.