Sure, they might sound the same (homophones are fun!), but to, too, and two, for example, shouldn't present an actual predicament. Same for they're, there, and their. All six of these words are basics in the English language. Sure, if you're typing quickly and just trying to get the words on the page, your fingers might lead you in the wrong direction. That's what proofing's for.
Sadly, however, a fella hired as a copywriter at a well-known advertising agency has had to have "to/two/too" explained to him. (Not once, I believe, but twice, even.) How does someone graduate college (let alone land a job as a senior copywriter at a national agency) without actually understanding the nuances of to/two/too?
Luckily, there are portable and handy references that can help folk with some of those trickster words. If you (or your malaprop-loving cube mate) are into coffee or tea, perhaps this set of grammar mugs will do the trick. Or maybe the humor of The Oatmeal will work better: You could buy this "ten misspellings" link in the form of a frame-worthy poster. Or if games help you learn the best, perhaps this one from Grammar Girl will be your new best friend (accessible on iPhone and iPad).
Whichever you choose for you or someone you know, hopefully, it can help rid the world of pesky, silly mistakes, one small sentence at a time.