Can a Graphing Calculator be replaced with IPod Touch?

Studentsa are spending almost $200 each on their "graphing calculators".  I need to know if "graphing calculators" can be replaced with an IPod Touch.  Please leave a comment for us as we explore the possibilities.  Here are the current apps related to "graphing calculator" in the App Store. 

1. Have you ever used any of these?  Feedback?
2. What capabilities and or functions do "graphing calculators" have that you can't live without?  
3. Are there educational issues related to students having multiple more functions with Touch at their disposal that would cause a problem? 

Have at this.  What do you think?  I will be contacting these vendors and any others to ask some math teachers to test pilot these apps sometime.  What are the positives and negatives?  Issues with testing? Etc.

Math Equation Solver - Review #2 by CLykowski

Math Equation Solver does exactly what is says, solves equations. There are no bells and whistles or high-end graphics included in this application. It is a straightforward, uncomplicated application made specifically for middle school, high school, possibly college level math. I would consider this more of a homework helper rather than an application to review facts or curriculum.

There are two uses included in the current version, two variable equation and quadratic equation solvers. You simply type in the numbers, press calculate, and you have an easy and quick way to check your homework and math skills.

Grade Level: Math Equation Solver is geared for middle school or higher.

Program Functionality: B / User-friendly and easy to navigate although actual directions are not included

Purpose: B / Works well for checking math assignments.

Overall Educational Value: B / This application would most likely benefit students at home when completing homework assignments.

Cost: $ 0.99

Requirements: Compatible with iPhone and iPod Touch. Requires iPhone OS 2.2 or later.

Recommendation: We recommend this app for personal use.

Creators Web site: http://www.koper-soft.com/

iTunes Link: Click here

-- CLykowski