One thing I've noticed as I surf the web and blogosphere is the growth of SEO. There are so many SEO related websites, forums and blogs it's incredible!
I suspect it's one of the few industries that will continue to expand during these harsh economic times. After all, if it's done well it has to be one of the most cost effective advertising methods available. Once you gain a top ranking for your chosen keywords you can reap huge benefits for a long, long time.
The recent experience of at least one SEO company seems to confirm this.