Outlook Attachment Alarm is a MS Outlook 2000/2002(XP) tool that will always remind you to add an attachment in case you forget to do it yourself.

Outlook Attachment Alarm is very easy to use and requires no hard tuning. You just specify the words and phrases that may occur in the body of the message and imply an attachment ("see attachment", "in attachment", etc.) and add these words to the Key words list.
Then Outlook Attachment Alarm scans all outgoing messages and if it finds words or phrases from the Key words list, it raises the alarm and suggests inserting an attachment.