This is a minor point, but I like it also:
ORIGINAL
print "Welcome to MyAddressbook. Please follow the prompts.\n"
print "If you wish to end data entry, you may do so at any time\n"
print "by type the word END into a prompt.\n\n"

BETTER
puts <<EOT
Welcome to MyAddressbook. Please follow the prompts.
If you wish to end data entry, you may do so at any time
by type the word END into a prompt.

EOT

Multi-lines string can be over-used, but I still thinks that the BETTER
way is really better in this case.

-- 
Renaud Hebert
phone: (33) 01 30 77 59 92
mailto:renaud.hebert / alcatel.fr