What makes task.fm different is semantic or natural language input. That means that instead of having to manually enter a date, time and event - like other reminder apps - task.fm is smart enough to understand and process your language just like another human can. For example enter "meeting with Jack next Tuesday at noon" and task.fm will recognize the date, time, event and will remind you automatically. If you are having trouble getting task.fm to translate your reminder, you can use the "advanced reminder" option to manually enter the date and time.
Unlimited email reminders are free. Task.fm charges a fee for SMS and phone call messages. SMS and Voice reminders cost 1 credit. You may purchase 20 credits for $2.
Superminder is an online micro-application that will make sure you don't forget. It was designed with simplicity as the main focus. It's uncomplicated and should not confuse you with options you don't need. It looks good with a friendly, stylish interface.
Superminder can remind you by email but you can take it a step further by enabling your cellphone to receive your reminders. There is a fee for this feature, however. SMS reminders cost 1 credit, 15 credits will cost you $4.
Wakerupper is a service to schedule telephone reminders. You enter text messages up to 140 characters which are then converted and delivered as speech.
No signup is needed for basic service. You can direct as many reminders as you like to any US or Canadian phone number. Basic service is free, but there is a premium version offering added features.
Wakerupper also offers a slimmed down version for mobile devices at http://m.wakerupper.com
This one is my favorite. From a remarkably simple interface, Remindr allows you to send reminders via Twitter, email, IM (Jabber or Gtalk), and/or cell phone.
It's totally free and no sign-up is needed. You can direct your reminder to any phone number or any email address so you can send reminders to others as well as yourself.
A couple of notes on Remindr: Time must be set in 24-hour format (2:30 PM = 14:30) and to get reminders via Twitter, you need to follow Remindr's bot.
So, don't forget to check out these handy services soon.