I have only recently noticed this although my experience with Twitter has been fairly limited until the last couple of weeks. It appears some devious spammers have learned of sites that track the number of times a given link is posted on Twitter (see Twitturly among others) and are taking full advantage of this by spamming their own links on the service. The Twitturly feed, which has mostly served as a fast-track for links that will soon appear on Digg and Reddit, has recently been hit with a number of links to a site that asks for your e-mail address in exchange for secret hints on how to last longer in sex. Personally, I find the Konami code has been the only secret I have ever needed in any walk of life (up, up, down down, left, right, left, right…).