Wakerupper - Simple telephone reminders

Use Wakerupper to...
Set a wake-up call at a specific time Remind yourself of important events Remember to take medication on time Escape from a boring date or meeting Remind child or spouse to do chores Set reminders for tasks and follow-ups.

I use this tool all the time for reminders, not wake-up calls. If you use more than 10 per day, there is a .05 charge which you have to pre-pay. They do give you a $1.00 credit if you sign-up, but that's not necessary to use the site.