Samsung Omnia i910

yes. see link: http://www.modaco.com/content/i9x0-omnia-http -omnia-modaco-com/278078/fixed-how-to-increas e-the-volume-of-the-verizon-omnia/

if you are unfamiliar with ANY of the terms or steps in the processes DO NOT DO IT, you can brick your phone.

You might also be able to convince a VZW tech guy in a full service retail location to do it...

A work around is to have an Alert Tone of your choosing in the MP3 Format which is recorded to a volume level of your desire and use that alert tone.
Load the MP3 into the "Root" of My Storage and select your Alert tone from there.