Visual Fractions -- Very cool fraction visualizer that lets create visual models of fractions as pizzas, bars and other objects. It also lets you save your model as an image to your desktop

Simplify Fraction Calculator -- Another very cool free tool from Math Warehouse. This one simplifies any fraction (including improper ones). Produces visual models of original and simplified fraction and it lets you save the entire thing as an image to your desktop.

Free Pintable Fraction Worksheets -- Several high quality fraction worksheets that have answer keys and also an associate powerpoint lesson.

Fraction Games Online -Several well done fraction games including

- Fraction Frenzy--a Fun game on identifying Fractions
- Equivalent Fractions Frenzy-- This one is on identifying equivalent fractions

There are some other really cool resources here