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.
retro retry retear retore retire reutter retiree redry ruder rater rider ritter raider rioter rudder redear redder redraw redrew ridder ratter rudery reader writer rattier readier reedier ruddier ruttier
metro retro tetri teeter deter strow retry peter troy poetry pedro nitro tiro toro trio trow outrow tyro foetor fetor hetero cuatro quieter meeter meter metre taro stereo stroy dieter tetra sheeter
ret reata rete retie arete fret fretty pretty reared reread reroute rewrite rewrote tret