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.
smush smash samshu smoosh smutch smutchy samech smooch sumach smoochy
mush smush mash smash mesh mosh much mushy ambush haimish beamish famish heimish immesh quamash gnomish rammish samshu shammash