Clients should help their own SEO cause
It occurs to me that as you get into more tactics that involve the social web, you should start leveraging the client’s staff (and possibly their customers) for assistance.
For example, what if you created a series of assignments to roll out over the life of your work with the client starting with each staff member tagging the company on delicious, then digging some page(s) on the site that they like, then creating their own lens on Squidoo.com, etc.
Providing instructions for your clients on how to do this would be part of the SEO consulting work you should be doing for your clients.
SEO is hard work and many hands make light work as my Mom used to say. Get your client’s involved and they will appreciate you efforts all the more and feel like they are part of the process and the success.