Crayon Physics Deluxe (App Store) is an iPod Touch/iPhone 2.0 game highly similar to Touch Physics (App Store) in that you must move a ball to the goal (represented by the star on the right) by drawing various things on the screen. For instance, to move a ball across a gap, you would simply draw a line with your finger over the gap.
The game has 50 levels, and it includes a level editor so that you can make your own levels to increase replay value. You can play straight through the levels, or use the level chooser to jump around and play any levels (useful if you get stuck on a particular level). The music is calming and the graphics are good, but the levels initially draw very slowly.
Some of the App Store reviews complain about not being able to draw and having to reboot the device. In my testing, I never had to reboot, but I noticed one obvious bug: sometimes when the ball moves, it doesn't move on my drawn lines; instead, it "floats" about 3 mm above or below the line which can then cause the ball to never reach the goal.
Crayon Physics Deluxe is available for $4.99 US, but you may want to spend $.99 for Touch Physics first to see if these physics-style games are your cup of tea.