I think one of the biggest impacts of Web 2.0 on nonprofits and small businesses in developing countires has been on collaborative and productivity software, which before, was typically:
a) expensive to buy
b) required particular computer systems /specs
With a lot of Web 2.0 apps, productivity and communication apps can all be accessed through a simple Web browser (though broadband access is probably a minimal requirement as well) now.
Off the top of my head, some notable ones I think include:
basecamp- project mgmt, todo lists, discussion boards in an easy-to-use UI, accessible through any browser
Google Docs- google does Excel, Word in a simple and collaborative manner, once again, highly accessible through a browser
Meebo-IM is not new in organizations, but keeping connected easily through any browser is, particularly with this Web-based universal IM software.
Especially with so much information accessible from all parts of the globe, there's been a greater need for translation services. One I've used is
Adsotrans (for Chinese translation). Combined with Firefox/Greasemonkey, you can essentially read any Simplified Chinese page in English; it's also leverage user-submitted definitions and translations to keep it ever-growing. There are plenty of similar sites that work for all types of language translations.