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.
hasped hispid
sped gasped lisped wisped hasped cusped rasped fissiped spaed misshaped souped gossipped zipped siped spued spud spied speed soaped seeped hispid zapped cuspid espied supped gossiped sopped vespid passepied sapped sipped