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.
lumbar lumber lamber limber lambier limbier lamer lemur limier limmer loamier
lumbar mimbar embar sambar mar lamber lumber member mair ambry number smear mare limber ombre camber comber somber summary dammar dumber tambur timbre umbra chimar ambary ember gambir mara sambur nummary amber cumber omber mammary maar cymar ambari samara simar hombre bomber sombre damar daymare tamari timber umber chamber shmear
lum limby slum plummy plumb glume glum flume blume alum luma louma limbo lamb limbi limba limb lamby lambie plum plume plumy slummy