It has become trendy to tack poems, photos, icons, logos and other digital flotsam and jetsam onto e-mail messages. We understand that digital signatures have a practical use, particularly when they provide the kind of info you'd see on a business card. And we don't doubt that, for some people, a U2 lyric can express how they feel better than they could. But the 3-D animations and other digital doodads created with the help of Meez and other sites of its ilk — Blingee, Iconator — are just plain annoying. They also clog the recipient's inbox with unnecessary bits. Sites like Smiley Central, which offers a seemingly endless assortment of cutesy creatures for dressing up e-mail, instant messages and blog posts, require you to download a browser plug-in. The company insists the app is neither spyware nor adware, but it can still slow your computer down.