non (core)invasive way to limit characters

What do you think is the best and non (core)invasive way to limit characters per row in blocks?

The issue: if some contributor gives a long word (or url) it leads to some css block level issues with tableless design in IE (but it works well in "normalized" browsers of course).

So the string like "check.mysupercoolwebsitetoday.url" would do HTML output to browser something like "check.mysuper..."

May it be some JS or filter or... It's needed exactly for (any) module generated block to avoid sidebar drops. It should not be php block.