<p>When I use traceroute, I often see abbreviations in the hostnames along the route, such as "ge", "so", "ic", "gw", "bb" etc. I can guess "bb" means backbone.</p>

<p>Does anyone know what any these strings abbreviate, or know any other common abbreviations?</p>

These are ISO-3166-1 Alpha2 geographical domain id's converted to lower case.
ge - Georgia
gw - Guinea-Bisseau
so - Somalia
bb - Barbados
ic - old code for Iceland?
Just look for ISO-3166 for the complete list of country codes. And RFC 1700 for the geo domain list.
Can you please provide the output from one of your traceroutes?
Hostnames using components such as bb for backbone and gw for gateway tend to put those towards the start of a hostname, e.g. bb1.toto.com.au or gw2.wtf.co.uk.
This follows a naming convention of more specfic to less specific elements in the name as you traverse from left to right.
Geographical domains are, almost always, at the end of the hostname.