PingMe is a service that allows you to set up automated reminders. You can get the reminders sent as email or as text messages to your cell phone. It's a well designed service that allows you to set up recurring reminders, share reminders with friends (you'll all get reminded that you're supposed to be meeting up). You can set up reminders using their web site, or you can text them to set up reminders. When you get a reminder, you can reply to have them remind you again at a set time in the future. They've got a lot of nice features like that that make this a really nice service.