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.
grumpy grump crump gramp crampy crimpy grampa cramp crimp
frumpy grumpy rump frump crampy crimpy crump grump trampy trump shrimpy
grum grume crumb crumby crummie crummy gorm gram grama gramma gramme gremmie gremmy grim grime grimy