A few categories to think about:
- Health; look at the CDC travel web site, but one might need a Yellow Fever certificate to enter some borders. Malaria, typhoid medicines, etc as well as making sure routine immunizations are up to date.
- Travel; look up the State Department pages to make sure you know where you need a visa, particularly in advance
- Travel documents; sometimes useful to scan to electronic form and then have available via internet or USB key. Also useful to work out some contact lists in advance
- Language; what level of language proficiency are you looking for

I wouldn't expect the travel on bike list to change much, though depending on the country - it can be a lot more expensive in terms of both $ and time to get something shipped in, so one might plan a bit more around that. If not too much of a specialty item, then depending on country you can pretty much get what you'd get in US - but you might need to travel to do so.

Also there will be some things that vary depending on the countries you are visiting. For example, for a lot of India or Southeast Asia, one could make a trip w/o a tent but instead stay in guest houses or hotels. I wouldn't do that in western China or a lot of Africa though. Many countries you might find things in the large capital cities (e.g. a Nairobi or Cairo or Santiago or Bangkok) but the trick becomes trying to figure out how to find these places, particularly if you aren't a native speaker. Climate and weather requirements will obviously also vary.