The Vim text editor has a set of selection commands for selecting various parts of the text while being inside them. Some of them are very useful - here are some examples:

1. To indent the inside of a block (after a copy and paste for example) use >i} or <i}. It beats writing >% and then doing <<%<<
2. To change a string use ci".
3. To delete a block use da}.
4. To copy a paragraph use yap.

Etc. Oh and try typing :he holy-grail in Vim (this tip courtesy of LeoNerd from Freenode who found it).