I came across a couple sites that have some interesting ideas to help you get the links coming to your site spidered more. Honestly,
I don't know enough about this stuff to know if it is white hat, black hat or whatever. I've got a lot to learn in this area.

When visitor visits, it pings the list ping server:
"what if everytime a visitor came to your website from a link, you sent a ping out for that webpage, to ensure that it gets in the search engines, affectively increases your pagerank? If you would like to increase your link saturation and thus your pagerank,"
http://linkyme.com/visitor-ping-hack/

More ideas here:
http://www.bluehatseo.com/category/blue-hat-techniques/

Please post if you knwo a downside to these, so no one wastes their time.

Jeannie