Google has implemented what they call recent mode. Recent mode allows you to download your email messages for storage on multiple computers.
Please note that this will only download email messages from the last 30 days.
To enable recent mode, first make sure that POP is enabled for your account. Instructions can be found at http://www.hawaii.edu/askus/1147.
Next, setup your username in your email client as recent:firstname.lastname@example.org. Please use your own UH username where it says.
For detailed instructions please visit http://mail.google.com/support/bin/answer.py?answer=47948.