It’s not the first time I see people that, to select feature by their fields values, use expressions like this:

"field" = 'value1' OR "field" = 'value2' OR "field" = 'value3' [OR ...]

A more practical and pretty way of doing this is by using the IN operator instead.

"field" IN ('value1','value2','value3'[,...])

This operator is available in almost every GIS software I know. In QGIS, it can be used even if there isn’t a small little button to click.
Captura de tela 2014-04-23 16.50.40

In fact, this is an abbreviation of what is used in SQL, where the operator is used in the WHERE statement:

FROM parks
WHERE "tipo" IN ('PI','CM','PJ');