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.
feebler fabler fabular fibular
feebler baler dibbler dabbler rabbler nubblier nobbler libeler labeler knobblier belier blear bluer abler babbler wobbler wabbler bubbler bubblier quibbler diablery rubblier pebblier nobler nibbler labeller libeller fabler gobbler gabbler cobbler cabler hobbler wabblier doubler wobblier