I found two simple, undated planners this week. The first is the Seeso Better Day Planner.
The Seeso Better Day Planner is a slim softcover planner with weekly planning on the left hand side of the page and a blank right hand page for notes and sketches. The Better Day ships with 2012 and 2013 sticky calendars that can be added to the book or write in your own dates. Available in four colors, each $14.
Vintage Year is also a simple undated weekly and monthly planner with stickers for highlighting and creating tabs for each month. I particularly like the quote on the cover: “A dream written down with a date becomes a goal A goal broken down into steps becomes a plan A plan backed by actions makes your dreams come true. Greg S. Reid” It appears to be a hardcover volume though the description is not specific. Its 4″x6″ in size for $20 from Anthropologie.