If you haven't stopped by Fourth Grade Studio lately you should know that Meg has finally released her fabulous fraction unit - based on her 16 blog posts about fractions. I have a copy and it is truly AWESOME. I've used parts of it already but am planning to do the whole unit next term as a fraction review with my grade 3s. It is absolutely worth the price - I promise you won't regret it if you want your students to think critically!!!
You can find it here.