Signatures

You already can! Just type [url*=yourlinkhere] your text here [/url*] Remove the asterisks and sub in your info, and it should work. 

If anybody wants to screw around with it but doesn't know any BBCode, here's some simple stuff you can do in the sig box:

To center an image/text, use [center*] and [/center*]
To adjust the size of your text, use [size*=?] and [/size*] Replace the question mark with numbers 1-7. 2 is the standard font size.
To add an image, use [img* src=yourimagelinkhere]
To bold, underline, or italicize text, use [b*], [u*], and [i*] respectively. 
To force a line break, use [br*]
To change text color, use [color*=red] and [/color*] Substitute whatever color you want. 
To change your font, use [font*=wingdings] and [/font*] Sub in whatever font. 

I dunno if that'll be useful for anyone, but there you go. Ha.