OK, so what can be used in Math classes?
What I've successfully used in Math Classes:

(1) Projects

--In-depth, somewhat open-ended investigations

--Long-term (2-5 weeks)

--Worked on in groups (mostly outside of class)

--Written Report combined math formulas, graphical representations, and writing (explanatory sentences to summarizing paragraphs)

(2) Activities

-- In-class work in groups on shorter problems

-- Often with individual or group write-up

(3) Oral Presentations

-- Individual or group

-- For classmates (sometimes with prior "coaching" @ office hours)

(4) Cover Sheets

-- Attached to each week's HW

-- Contain "what I learned this week" summary

-- Entries on "What I'm confused about this week"

-- Graded check/check-plus/check-minus/zero

-- Students are encouraged (via my comments) to elaborate further (next week), to flesh out meanings, and to give concrete examples

-- Students can informally make suggestions or ask questions too embarrassed to ask in class