I hang with a short-attention-span crowd — so we're always changing our job/direction/passion.
I like this “How To Be Creative” manifesto a lot. It encapsulates many of the ideas that I share with folks when they are in that creative, unfrozen, floating period between gigs. This is kinda like Powdermilk Biscuits — gets you up and doing the things you need to do.
I also like the whole Change This site — comprised mostly of “manifestos” by irascible opinionated curmudgeons like me.
I came across a web-development manifesto – “One Minute Site” – which spoke loudly enough to get me up off my rusty dusty and plug some changes into my sister's web site. One Minute Site is a great rant against the overly-complex, overly graphical/technical sites that “web developers” foist off on their clients. I've been making the same rant for ages, as have many of my good web-dev friends, but One Minute Site does a great job of presenting the argument.
I'm happily pecking my way through the rest of the site — I bet a few more manifestos make their way into this blog.