Note taking

I use:
OSX http://brettterpstra.com/project/nvalt/ I use this
OSX http://culturedcode.com/things I use this

of intest:
OSX http://markedapp.com/
OSX http://brettterpstra.com/a-service-for-sharing-dropbox-link-collections/
OSX http://www.caseapps.com/tags/

OS integration and globals

I use:
http://growl.info/ I use the old one for snowleopard, I didn't have to pay
http://wafflesoftware.net/growlergn/ I use this
http://www.orange-carb.org/SBM/ I use this
http://www.lightheadsw.com/caffeine/ I use this
http://manytricks.com/butler/ I use this

if interest:
http://www.macbartender.com/