World Without Borders will host the monthly User Group Leader Chat tonight at 6 p.m. (Pacific). One of three user group-oriented chats each month, this event is not just for members or leaders of Mac User Groups, “but warmly welcomes anyone interested in the world of user groups,” according to The Mug Center, an online resource for MUGs. Jim Foster of Macintosh Users East is tonight’s guest; he’ll talk about joint activities between Mac and PC user groups.