If you're able to change the content of the word (either hard coding or through a CMS), then you might be able to use a zero width space, or the <wbr> element.
They both have problems in various browsers/fonts, so I'll point you to a couple of references: http://www.quirksmode.org/oddsandends/wbr.html http://www.thescripts.com/forum/thread154142.html
That is certainly a long word! One solution in this case might be to shorten the URL with the use of the mod-rewrite function in the .htaccess file. Otherwise use the organic link information that should really be embedded for accessibility, e.g. rather than -
testOfTheLongestURLICouldThinkOfToMakeThisNotWra... use "Click here to see an example of a long no-wrap word"
The element would also work fine, however it does not work in all browsers. As the first example provided by Linsay explains, the tag does not work in all browsers and has trouble with some popular fonts. Therefore I would opt for mod_rewrite to reduce any redundant information or using organic language to describe the link as opposed to the full url. See here for information on mod-rewrite.