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.
knifed naffed nighed neighed nifty knight navaid nevoid naevoid naivete naivety nightie
coifed waifed wifed fifed knifed fed feed huffed vied baffed luffed leafed hived bifid dived whoofed buffed loafed goofed lived quaffed pouffed doffed coiffed sheafed chivvied waffed naffed feod waived savvied cuffed roofed riffed reified refeed reefed beefed feud whiffed boffed ivied biffed levied offed wived chefed gaffed refed jived puffed reffed feoffed miffed defied chafed chevied muffed reived rived ruffed daffed deified divvied tiffed poufed piaffed hoofed woofed chaffed cheffed chivied chuffed yaffed
knife naif neif sniff sniffy unify