Ilija recently add some tweak to the code, where you can sort your tasks based on alphabetical. See http://www.activecollab.com/forums/post/4642/#post4642

You can use this feature to re-order your task based on whatever criterias you might have. For me :

* Use * in front of the task to inform that the task is the highest priority.
* Use number (1,2,3...) to sort the priority of the tasks. "1. Web design", "2. Tweak code"
* Use @ in front of the task for information on place. For example "@client : presentation to the Manager"