As you are probably aware, Rustybrick and his gang are doing a bangup job reporting on the sessions they are attending at the SES San Jose conference. Of course, you can find all the coverage at www.seroundtable.com, but one report in particular caught my eye. It is Search Engine Q&A On Links, which was a session where Matt Cutts (Google), Tim Mayer (Yahoo), and Kaushal Kurapti (Ask Jeeves) answer questions about links and urls.
Of course, the standard advice is given by Kurapti...Avoid link farms, cloaked pages, invisible or hidden links and links by images - text based links can be understood, but not image links. Become an authority on a specific subject. Focus on your business and content and the rest will follow.
Then Tim (Yahoo) mentioned a new Yahoo! tool called Site Explorer, but the link redirects to the standard advanced search page, so I guess that isn't working yet. Still, it sounds like it will be interesting when it is working - sounds like it will give some advanced backlink and site: information.
Some tidbits mentioned...
Matt, regarding anchor text and OOP (Over Optimization Penalty): Most natural links are not 100% one exact phrase to the site. It won't hurt you, there is no OOP, but all the links might be devalued.
Matt, regarding query strings at end of urls: 3 or more, its not great, but GoogleBot sometime is smart. Don't use id= in it, and if you have numeric parameters, dont go above 4 numbers.
That's the first time I've heard a specific number mentioned in regards to numeric parameters. I knew that Google didn't like long numeric parameters since it could look like a session id, but the exact number 4 is new to me. Good stuff.
Tim, regarding dynamic urls: If you have inbound links to those dynamic URLs, they will more likely crawl it.
Another interesting thing that was brought up today was that Matt Cutts announced his blog - www.mattcutts.com/blog. I'll be checking in on this blog occasionally to see what Matt has to say.