ive made a auto poster that i posted in the tools section culd very easily be moddied to just create user accounts on vb forums
some do not have capthca enanled and you could sign up to them automaticly
most do have capthca enabled, so you whould need to first get the sign up page, retivive the capthca, keep the connection alive, enter the capthca image the repost signup page with the corrcect capthca string
its not that hard to do, once you have some basic code to work from like the auto poster i created already
one good way around doing all this yourself whould be to have say a site of your own doing it for you
for instance say you have a adult free site, that gets 20-300 hits a day, simply on the front page enter a little capthca that the user has to fill out in order to get all that free porn
but you index page has curl/php behind it, it goes to a sign up page retives a capthca from the sign up form, displays it in your porn sites index page for poeple to enter, once the do, the info is sent back to the forum sign up page and you have a new account, and the unspecting porn surfers gets there freee porn, everyone wins
you whould of course need a big list of email accounts to sign up to, as most forums only allow one account per emal, but first you could simply modiffiy the code to siign up for free email accounts, storing the accouns info in a database as it goes, then once you have a few thousand switch it over to the other task