Just type "Choose next Guy vs. Guy topic by next Thursday," for example, and task.fm automatically creates a reminder called "Choose next Guy vs. Guy topic by" and assigns it to Thursday, May 21. The service even automatically schedules an e-mail reminder.
The service --including the e-mail reminders -- is free, but if you want voice or SMS reminders about upcoming tasks, you'll need to purchase credits (one reminder per credit). Two bucks buys you 20 credits, but you can also get 100 credits for $8.
To be honest, I'm in love. I really like the non-nonsense interface and the fact that there's no need to futz around with setting due dates and priorities and categories and what-not. Sure, it's not as powerful or flexible as my other favorite to-do tracker, Doris, but I'm a sucker for services like Task.fm that are smart enough to genuinely simplify your day.