Q: i have a new iphone 4s but it is not giving me all available memory. its a 16GB. only 11.9 used and its telling me i have 1.7 free???

iOS 5 itself will eat up several gigabytes of memory. This is normal.

I was about to say the same thing the OS is taking up some GB's I wondered the same thing when my 32GB showed only 28GB available.

According to the article http://support.apple.com/kb/TS2419

When you view the storage capacity of your iPod, iPhone, iPad, or other electronic devices within its operating system, the capacity is reported using the the binary system (base 2) of measurement. In binary, 1 GB is calculated as 1,073,741,824 bytes.

For example: The way decimal and binary numeral systems measure a GB is what causes a 32 GB storage device to appear as approximately 28 GB when detailed by its operating system, even though the storage device still has 32 billion bytes (not 28 billion bytes), as reported.