I've taken a list of English words, and examined each of them to see what they sound like (using the PHP metaphone function). This page lists the most common metaphone codes, along with their words. You can also search for a word of your own, and see which words sound similar - and which ones rhyme, and which ones alliterate.
rad road read raid radii readd ready radio rid rod roadie rat roadeo red reed rood rate rede rued rode redd redo rota rude rudd ride rato rowdy raita riata ruddy ratty rodeo reata rhyta reedy redia wried rediae