MrHard - 9:12 pm on Mar 23, 2010 (gmt 0)
It also works both ways,
You can sign up for an SEO, see what they are doing monthly, and then cancel and do the work yourself, which is pretty doable if you have the time. This wont keep you up on the latest trends however. You will probably also find that they don't reveal their true secrets so easily, but rather keep those for themselves and just do things you already know how to do.