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.
whaps whaups waps whips whops whups wheeps whoops whipsaw wops whoopees whoopies weeps wipes woops weepies
haps whaps chaps shops cheapos chips rapes papas laps lapse lapis caps capos gapes jaups japes shapes yaups capes leaps saps zaps naps tapas napas tapis maps whaups whops chapes hops waps apes neaps tapes gawps apos gaps apse baps wraps apps kapas paps hyps taps daps napes knaps heaps hips whips whups soaps raps reaps cheaps chops ships yaps yawps
whap wap whaup whip whippy whop whup swap