Searching in apps i've found kroneko as a front end for cron, at and others. A good option for linux i think. Found at http://www.kroneko.bounceme.net/kroneko/eng/
Steps to Reproduce:
Please look at http://www.gentoo.org/doc/en/gentoo-howto.xml for instructions how to create ebuild files.
The url seems to be dead right now, also I couldn't find much information about
this app at all, seems to be discontinued.
Please reopen if this is still available and there is a website available somewhere.
Not personally interested, but:
The URL from Jeff Davidson is ok. Thx
Upstream hasn't had an update since 09 of 2003, closing as WONTFIX.