Katie Holmes -- Grateful Dead Inside

4/15/2009 2:40 AM PDT BY TMZ STAFF
Wearing the latest in Scientologrunge-meets-hippy chic, Suri Cruise's birth mother converted ... back into Joey Potter on "Dawson's Creek." 'Memba her?!

Katie's to-do list: Hackey sack in the quad, ultimate frisbee game in the park, shower, late night drum circle....