Last week (Saturday 2008-04-05): 37 miles, to Chicago just north of Promontory Point and back.
This week (Sunday 2008-04-13): 33 miles, to Chicago Botanic Gardens. North on Sheridan and Green Bay Trail, south on North Branch Trail with an extra loop around Skokie Lagoons.
Next week (???): \~40 miles, probably down to Chicago again.