Just go to your local music store and inquire about portable DAWs and digital recorders etc. Also, you would still need a good mic. A PZM perhaps because you really don't want to pick up any ambient noises along with your vocals. Get a nice note going and somebody drives by with their car radio cranked up.
-ED-
_________________________
A gentleman is one who never hurts anyone's feelings unintentionally.
- - - Oscar Wilde