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.
rubus rubs rubious rebus rubes rebuys rubies ribs rebs robs rubbies rubasse ribes robes rabbis rabies rebbes ribose rubace rabbies
rubus bubus bus tubas bubs cubes daubes subs rebus fubs pubis dubs tubs jubas lubes gibbous hubs habus phoebus fubsy nubs abuse boubous buys rebuys zebus subas rubes babus rubs cubs niobous pubs jubes buss busy pubes daubs tabus tubes chubs
rub rebuy rubby rube ruby grub grubby krubi drub