Make it nearly impossible for you to forget an important reminder or event with Remindr, a free multi-medium reminder service that doesn’t require registration or account sign-ups. Written as part of a Ruby on Rails coding contest, the simple webapp asks for a reminder text, date, and time, then lets you enter a Twitter account, email address, Jabber/Gchat IM name, and mobile phone number for SMS alerts. It’s not the spot you’d go to for regular alerts, but for one-off, must-not-miss things, Remindr can be pretty handy.