Via Mr. Verb comes this citation of a joke about strong verbs in The Onion:

Adrian, MI - After a week of precipitation, Kelly Knoke has started using "snew" as the past tense of "snow," just to mix it up a little.

Whenever the subject of strong verbs comes up, I can't help remembering a remark of Seth Lehrer (who was my adviser when I was an undergraduate) made once about strong verbs. He pointed out how odd it was to think that there is something inherently "stronger" about verbs that change their inflections with internal vowel alternations (swim/swam/swum and the like), as opposed to inflectional endings like -ed. Now for a really strong verb, he went on, there's a verb in ancient Greek that means "to be sodomized by a 12-inch-long white radish." Although that translation is a little over-specific, there is a verb, ῥαφανιδόω, that appears in Aristophanes's The Clouds and which Liddell and Scott define as "thrust a radish up the fundament." Since the radish in question is probably a horseradish, we can probably take the the size and color are probably implied, although not lexically specified).