As many as you want. I currently have over 500 on mine.
It depends on how many GB you have.
There are 15,000 Applications!
The Ipod is capable of holding 11 full pages of applications on a 3rd gen itouch, and on a 2nd gen, 9, iphone, idk
The iPhone has thousands of free applications, including food diary applications. Fatseeker and GoMealsHD are two apps that are free and have received good reviews. There are many more using the search feature on the iPhone as well.
7-10
About 4000
it depends on how many gb's you have.
Almost all of the applications on the iTunes store is compatible with the iPhone 4. Exceptions are applications which are for the iPad.
Yes.
About 20,000
I THINK IT HOLDS AS MANY AS YOU CAN PUT ON THERE.
Yes It Does, If You Download To Many Apps Or Run To Many Applications At Once It Might Glitch
2000 songs