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.
syrups sirups sarapes serapes surpass sourpuss
larrups chirrups syrups sirups urps rips raps groups hydrops drops carps dorps chirps sharps troupes traps fraps croupes craps corpus corpse corps gorps props burps bewraps wraps croups drupes drips reps preps herpes roups harps carpus rewraps grips crops tarps trips turps warps perps sherpas