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.
frets ferrets fretsaw forts frits frats farts fortis fortes frites fritts fruits fordoes forties ferrites foredoes ferrates ferities fards verts fritz fords varieties vertus virtus frauds fiords farads virtues veritas verites virtuoso virtuosi virtuosa faradays variates phorates faradize faradise virtuous verities
barrets trets rets carets frets garrets curets terrets berets burets ferrets turrets arts frats greats greets tarts courts karts brats curtsy borts artsy airts carrots treats hurts morts boarts drats parietes vertus gourdes aortas rats shreds shirts charts worrits warts tortes territs parrots derats sorts prats grots merdes trots crits farts cartes bruts keiretsu reds pierrots grits kurtas merits marts fortis parts cruets hordes korats brits hearts quartes ports virtus girts harts forts rots ruts bardes quartos fortes verts darts quirts aretes orts frits nerts jurats creds karats dirts carats carts tortas tarots torts writs certes quarts whorts worts cherts shorts yurts
fretty fret fared fart fired foredo fort forte forty frat freed fried frit fritt afreet