Hullo Mark:
Thought as much, really. Why else?
But given that, and supposing you want to write in a spectrum of the classic verse forms in English, it's not just hard but Herculean. Which is not to say impossible. Such an algorithm would have to refer to a fully phonetic dictionary, since it's not just the syllables that would need to be counted, but whether they were accented or unaccented (or in Latin, and inferentially I suppose some Romance languages, whether long or short - the distinction comparable to that between the vowel in "barn" and "that", in English) and then whether trailing or leading, and their cycle of recurrence. Add to that an exceptions list of acceptable elisions that a reader can readily accommodate without disrupting the rhythm, and even Sisyphus might quail at it.
On the other hand, if you've got any programming friends, and can make a case for say, an educational as well as specialised audience for it: well, you never know; although localisation would be formidable too, and would require an extremely rare talent or tricky collaboration (bridging C.P. Snow's "two cultures", no less, to achieve. But don't hold your breath.
Why not spend it, instead, on some thoroughgoing reading aloud of the greats in your chosen metres. Risk occasional laryngitis, but in the process absorb them as second nature. Sometimes you'll still want to count - rather like musicians: a bar or so to start, or to measure a climactic pause. But for the rest, the rhythm will carry you, and your reading aloud reinforce your silent internal verbalisation. (Nobody speed-reads verse if it's any good).
Then be sure you can touch type at reading speed. Check your system isn't one of those that has speed problems with Pages, and enjoy its intuitive beauty to let your words flow like nectar: from your singing mind to the page.
Or battle on as you are until then - and here's a little anecdote to tide you over until technology catches up with you, or you leave it with not a chance.
The internationally renowned Australian Poet, Les A. Murray, confided to me once, in our late twenties or so, that he'd decided to write verse because prose left the other end of the line to far away to face. He measured his progress in carriage returns on the little portable typewriter I'd not be at all surprised if he still uses. And I doubt he ever counted past three, except for the cows on the farm and his offspring.
Les generally writes in free form, but the world of poetry is well aware of his frequent allusions to, and occasional excursions into the heritage of verse.
Cheers.
iBook G4 Mac OS X (10.4.4)
