Remind yourself in two and a half weeks to call your grandmother for her birthday: use programmer Ben Sinclair's new web application FutureMail.
Write yourself an email and schedule it to be sent at a future date. Similar to a previously posted method of using Yahoo! Calendar to notify yourself of upcoming events, but with RSS and a "FutureMail" blog (and without the ability to set up repeating events.)
FutureMail [Ben Sinclair]
Related:
Event reminders with Yahoo! Calendar