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.
spared sparred speared spored spread spired sparid speered sparoid supered speired spurred spiered spoored separate sprite sporoid spiroid superadd zippered spirt sprat sprit spurt sport superette superroad suppurate spirit sporty sprout seaport support
appeared spared pared reappeared speared coappeared zippered rapiered paupered coopered loppered repaired lippered jeopardy spired spurred coppered pried jeopard capered sparred speered spiered spoored spread supered diapered chippered copyread tapered lappered sparid pureed pored peppered papered lipread vapoured kippered preed peered speired parred spored parried purred pard paired repoured poured leopard pardi vapored pardy choppered
spar spare sparrow sparry sprue supra spree spurrey spur spry spirea spray spiry spire spiraea spear spurry spore osprey