Rupert made this great video for getting search engines to find your Wordpress blog: http://twittervlog.tv/2009/04/seo-for-videoblogs/

And he lists basic stuff you can do now which will have a big effect:

• Give each post an HTML page Title with keywords in it - subjects discussed in post, etc.
• Change your blog template so that your blog post title is an H1 level heading, and make your blog post titles have useful keywords that describe the content of the post, with the same or slightly different info to the page Title (above)
  • Most blogs' H1 is their blog name (from the blog header), which is hopeless - Google looks for H1 to see what the page is about.
• Add meta description and keywords in your HTML HEAD.  If possible, make them different for each post - don't believe the people who say this has no effect any more - I've tracked it working on Twittervlog.
• If you have a Wordpress blog, you can handle the custom Title and meta tags using the All In One SEO Pack plugin. Otherwise you need to hand code the changes in your blog template.
• Make an XML sitemap in your root directory, to Google-preferred specs.  If you have a Wordpress blog, you can use the Google XML Sitemap Generator plugin to generate this dynamically.
• Get backlinks from other sites, and make sure the link anchor text has keywords in it - not just "The interwebs" or your URL.  Get links from sites with good Google PageRank, they will pass good PR juice onto you and start giving you a better PR.
• If you want, you can track all your performance using an app like Advanced Web Ranking.
• Search for popular phrases that you want to rank well for, using the Google Keyword Tool.