<p>The activity monitor in sql2k8 allows us to see the most expensive queries. Ok, that's cool, but is there a way I can log this info or get this info via query analyser? I don't really want to have the Sql Management console open and me looking at the activity monitor dashboard.</p>

<p>I want to figure out which queries are poorly written/schema is poorly designed, etc.</p>

<p>Thanks heaps for any help!</p>

Would the SQL Server Profiler do what you need?  I haven't used 2008 yet so I don't know if the tool is still in there but if it is I believe you can set up a trace to log queries that meet specific criteria (such as those that execute and drive CPU up above a certain threshold).
We've used this on our project and it did a pretty good job of helping us troubleshoot poorly executing queries (though don't leave it on full time, rely on the general Windows Performance Counters for performance health tracking).