Obscure undocumented tips, tricks, and trivia

Q: How can I get the Filer to run a program based on a files type?

Q: How do I prevent the 100/200LX from powering down while on batteries?

Q: In setting up a program in Applications Manager, what do the upside down question mark and the inverted exclamation point do when used in the Comments field?

Q: How can I customize the fields in the PhoneBook? (e.g. add an E-mail address field).