memory leak stomping

I'm looking for tips on how to stomp memory leaks, as I haven't a clue
how to do it properly. I have a very young Rails 2.0.2 application
that jumps from 180mb total usage to 510mb total usage in about
60-90mins. I tried using Dike and could not make heads or tails of the
data. All I know is that the heaviest page on my site,
dashboard#index, was producing 700,000+ String objects according to
Dike, but I have no idea how to reduce that number, or where to even
start looking. (As a primitive experiment, I commented out all the db
queries in dashboard_controller and only reduced the number of string
objects by about 30,000.)

Some other info about my app: we use Rmagick fairly extensively, but
there's almost no traffic on the site right now as we still in a
closed alpha testing stage. There are also fairly db-intensive
routines in dashboard which compiles user and friend activities over
the past couple of days. I haven't introduced any form of caching yet,
although I'm looking at Interlock/memcached.

Any tips or links to good tutorials would be really helpful. I've seen
all of the various solutions for finding leaks (Bleakhouse,
MemoryProfiler, the aforementioned Dike), but unfortunately, I don't
know what to do after I've established that there is in fact a leak.

Thanks

:luis

did you work through these?

http://blog.methodmissing.com/2007/5/10/rails-memory-usage-case-study/
http://codehappy.wordpress.com/2007/01/17/tracking-a-memory-leak-in-rails/