So, for those of us not really organized enough to keep track of our periods, resulting in monthly surprise periods, pregnancy scares or embarrassment when the gyno asks you to list the date of your last period and it takes a really long time to work it out… Comes this nifty site, mon.thly. You give them the date of the first day of your last cycle (I know, but you're at home so you can take your time), and they then calculate the date of your next period and e-mail you a reminder. Oh, and it's free. This is why the internet was invented. [mon.thly]