I like split infinitives. Consider: to boldly go where no man has gone before is so much more powerful than "boldly to go" or "to go boldly" (ick). For me the general rule is that it's best to place a modifier as close as possible to the term it modifies (as in only if), and if you can prevent a "to" from getting between your adverb and your verb, more power to you! I realize that a preference for the split infinitive borders on grammatical heresy in some parts, but then again I like the word ain't, too. :)