Any side-effects from using executionTimeout?

We've had some thread aborted/request timeout error in our web app and I've been
looking into using executionTimeout to increase the amount of time that the
server will wait before aborting the request.  Are there any issues we need to
concern ourselves with by setting this to a higher value such as traffic to our
site being blocked by others running processes that take a long time or the
server cpu getting maxed out?

Like you hinted at the biggest threat to extending the timeout, is that if the
long process that is running is locking the database or other application
resource you'll run into problems.  One way around this if there is no way to
make that process faster, is program it to run asynchronously, this can be
tricky because you now have another process that has gone off and done
something....you need a way to be notified when it's done...it's a lot more
challenging than you might think and a simple blog post probably won't solve it
for you...here's a link to a primer on it and some code samples:
http://msdn2.microsoft.com/en-us/magazine/cc163725.aspx

Ryan