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.
seamier seamer seemer semiraw smear samara sambar sambur simmer smeary somber summer samurai summery simar summary zamarra zamarro
foamier seamier loamier gamier beamier amir hammer mimer maimer jammer jammier lamer limier fumier hammier gammier lamber boomier gammer reamer roamer rummier gummier doomier wombier chummier yammer camber aimer gambier camera gemmier gambir seamer foamer namer mammer ameer lambier limbier rammer gamer homier roomier amber rammier rimier dammer tamer chamber shammer yummier mir