Beware, nerdiness follows: I generally like my BlackBerry 7130e, but its multiple letters per key can sometimes give the wrong result. Using word frequency lists from the British National Corpus, sqlite, and way too much programming time, I determined that the key sequence with the most possible word results (81?2) produces best, beat, neat or nest. The device itself suggests also brat and bray, so I should try a longer word list — in my copious free time, of course.
The longest (common words in the corpus) that have the same key sequence are employers and employees, which might briefly cause hilarity in an HR or legal context.