From: salvav@vccsouth08.its.rpi.edu (Vito Salvaggio)
Just some stuff Vito found around the net.
None of these is his work.
(AKA Authors unknown)

Constitution Class: USS Enterprise NCC1701
__________________ __
\_________________|)____.---'--`---.____
|| \----.________.----/
|| / / `--'
__||____/ /_
|___ \
`--------'

Constitution Class: USS Enterprise NCC-1701 Refit/NCC-1701A
___________________ _-_
\==============_=_/ ____.---'---`---.____
\_ \ \----._________.----/
\ \ / / `-_-'
__,--`.`-'..'-_
/____ ||
`--.____,-'

Excelsior Class: USS Enterprise NCC-1701B
_
_______________________ ________.--'-`--._____
|____==================_) \_'===================`
_,--___.-|__|-.______|=====/ `---'
`---------._ ~~~~~|
`-._ - - - ,'
\_____,-'

Ambassador Class: USS Enterprise NCC1701-C
___________________ ____....-----....____
(________________LL_) ==============================
______\ \_______.--'. `---..._____...---'
`-------..__ ` ,/
`-._ - - - |
`-------'

Galaxy Class: USS Enterprise NCC1701-D
_____
__...---'-----`---...__
_===============================
______________,/' `---..._______...---'
(____________LL). . ,--'
/ /.---' `. /
'--------_ - - - - _/
`~~~~~~~~'

A concept for the Nova class starship, from pg 178 of the Tech Manual:
_____ _____
____ /-----`-----'--.--`---...____
_________/___/_______|_|==|===|=====|=====|===|===`
(_________________LL<_) `---`-..__|__..-'---'
,/ /_------' . . ,--'
_/ ( `./
'----------_ - - - _/
`~~~~~~~'

Dan