Asynchronous Script call in CI

[eluser]Unknown[/eluser]
Hi all -- newbie here.

I've an application that takes user input, saves to a database, compiles an email and
sends a redirect page back to the user. The user, while this is going on, is held
hostage for 5 seconds or so while the script completes.

Is there anyway to send back the user page and continue with server processing?
How could I do that instead of having them wait for the <return>

Thanks!
-Dev