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.
gulpier gulper gloppier galloper caliper clapper clipper calliper
gulpier pulpier walloper sloper sleepier lippier loopier loper loppier eloper flappier helper leper caliper calliper galloper gloppier gulper pulper floppier slippier sloppier yelper