Typo of <3 (heart symbol, tilt your head to the left n00b =P)
Usually occurs when the shift key is held down to type the "<" and not released in time or at all to type the "3", resulting in "£" being typed instead.
Usually used in chat rooms or web messenger applications such as MSN.
Amy: I <£ you Liam
Amy: Eek I meant I <3 you
Amy: Pfffft look up <3 on Urban Dictionary.
Lazy way to type "Gold digger". A partner who only wants you for your money.
"I'm not saying she's a <£"