We just switched to VoIP and in the process installed a semi-large Vonage box into my bedroom. I now sleep with the shimmer of quicky mart blue from its always glowing LED lights. If you wanna circumvent the large and glowing, then the SmartLink Micro Analog Telephone Adapter (M-ATA) by Patton is probably a great option. We’re not sure if it will work with any VoIP service or if comes with its own, but at just 3.6″ long by 2.1″ wide by .78″ high and .2lbs it makes this device an obvious choice for any road warrior or aesthetically sensitive folk. Includes caller ID, call blocking, call waiting and works with firewalls and faxes. Looks like an AC adapter is required for use, but hey, this thing is still really small.
Super-small VoIP adapter for phone, FAX [MobileMag]