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.
gars guars gaurs cars grees greys gurus carse gorse cares grues gorsy grays gross gores grass carrs goers grows caries grouse caress karoos grease guiros grassy greasy kaross coarse kauris carouse quaeres carries carious gurries karroos kauries cors cris carassow quarries curs kors crus kirs kris crews kiers grace curse crass koras cures cries cores cress corse cross kurus graze crows cruse currs keirs coirs craws
ars bars pars nears gnars lears maars bears boars ears guars fears feuars tears dears wears sears shears rears fiars vars gears oars knars mars lars liars cars jars gars haars hoars hears tars soars wars roars chars pears years