Since IALs exist to bridge language barriers, if the world isn't interested in them as of yet it stands to reason that we might be interested in other less dramatic methods to facilitate communication on a smaller scale.
There are some pretty obvious linguistic areas of the world that need tweaking, that would help bridge language barriers at least a few million at a time. Some examples might be:
-writing: Kazakhstan is planning to switch to the Latin alphabet within the next decade or so, and that's a good thing as it'll help facilitate communication between Turkic languages. Uyghur is another language that could benefit from this. I'm of the opinion that Persian should switch over to the Latin alphabet as well since the Arabic alphabet it uses is rather silly considering its lack of short vowels. There are a whole host of examples in this area.
-vocabulary usage: most people don't know which words in their language are shared by others. The average English person doesn't know that water is Wasser and book is Buch, that international is internazionale and so on. There are also a lot of redundant or somewhat overlapping words in each language, such as dog and hound and street and road. It would be interesting to create a forum with a script that changed what a person types in their own language into words that are more easily recognized to others when the word is redundant. It would make things a bit awkward here and there (since not every dog is a hound) but it might be an interesting experiment to see how easy it is to read what other people are writing in their own language. Some changes to the writing might be possible as well, so if a user is registered with English as his native language the German Wasser would change to Water, Dutch zon to son and so on. On the other hand, a person with German as his native language would have a screen that changes English help to helf and so on.
-There would even be some immediate use for this where a company could put their correspondences through the tool to make them a bit more legible to people in another country. It would be free, and there would be no worries about a weird machine translation. I guarantee that a great number of companies would often use this tool if they know it's guaranteed to make their correspondences that much easier to understand.
-Promotion of language standardization, languages worth learning and bilingualism - if you're of the opinion that the languages of the world are eventually going to merge into a big creole the best thing to do could be promoting an existing creole. Bislama for example is mostly standardized but the orthography isn't quite 100% fixed so this is your chance to promote the one you think is best (probably the most phonetic one), so you could start a website in the language (forums for example) that uses the orthography you prefer. Or perhaps the best way to promote the language is to improve the economy of the country that uses it (so that people have more time to use the internet and think about other things besides day to day life) so that could mean volunteering to build houses in Vanuatu or somewhere. And of course bilingualism never hurts (it's usually passed on to your children if you have them) so if you're Canadian and haven't learned French yet, that might be a good idea too.
Any other ideas?