I am looking for a lightweight Mac application to create and lookup short texts like e.g. commands on the fly. Maybe a menu bar application. Extensive keyboard support would be great. 
I used [nvALT](http://brettterpstra.com/projects/nvalt/), but a regular window needs to be opened. Applications like Evernote are overkill. [Dash](http://kapeli.com/dash) has a cheat sheet feature, but it needs some effort to implement individual entries. 

Any ideas?