asterisk users - Nov 2004 - Queue calls- multiple to same extension, max extensions?

By design, it seems that when an agent takes a call, the next
call is not (also) sent to his phone (strategy=ringall)

Is there a way to force asterisk to also send the next queue
call to the same agent that is on the phone?  (So the agent
can answer via call waiting.)

We are using queues as a ringall type situation, with the added
feature of being able to have agents login/logout when they don't
want to be taking calls - but, there are times that there will be
2 agents logged in, but only one really taking calls.  

Also, is there a maximum number of destinations in a ringall
queue?  If there is a low limit, is there an easy way to raise it?

Any answers appreciated... been having intermittent wiki problems
for the past hour or so.

thanks
bill