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.
quacks quicks quakes gucks quags quickies guacos cuckoos quokkas guaiacs quaggas kakis cooks kakas gawks kecks cakes kicks cocks cukes cokes cacas cacaos caucus kaiaks caiques cookeys cookies gawkies
hacks backs shacks whacks racks tacks wacks wracks jacks yacks lacks packs quacks knacks macks sacks lacs ricks picks jauks pucks gucks bucks hicks bocks pecks pacs sicks kakas sakes gawks makes paiks guacos beaks leaks dawks gecks soaks fakes rocks dicks wreaks oaks jockos ticks yoicks yaks shucks shicksa shakes chocks checks rakes wauks kakis becks wackes takes rakus shackos tacos pocks sickos sucks auks quakes pacas cakes hucks ducks wrecks recks fucks mucks quicks macs licks socks jocks wackos hawks makos jakes cocks haiks bakes vacs sakis mocks fecks necks geckos sacs hoicks lucks nocks knocks lakhs ruckus kecks buckos kicks hakes docks locks wricks lakes nicks rucks laics kaiaks cacas peaks daks rakis hocks micks decks hecks takas teaks tucks wakes whackos wicks chicks chucks guaiacs shakos shocks hakus yocks yucks
quack quacky guaco quag quagga quaggy quake quaky quick quickie squawk