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.
rumour rumor rummer remora rummier rimer rammer reamer rhymer rimier rimmer roamer roomer rammier remarry roomier
humour rumour tumour amour mor mora tumor more tamboura mura demure mure sambur remora moor humor memoir memory rumor murr immure demur femora tambour lemur tambur femur
rum rumba rummy arum brumby brume crumb crumby crummie crummy grum grume drum trumeau