I've recently filled up most of my Droid with apps. Some are used all the time like FBReader. Others get pulled up occasionally. Not everything fits on the 16Gbyte flash card so there is a limit on the number of apps you can install.
Lately though I have been paring down the number of apps. Not because of space but because of updates. It seems lately that all the apps want to know where you are and what you are doing. They want access to email and SMS. Of course, why a dictionary app needs all this to look up some words has nothing to do with how the app works.
Of course most anyone that has played with a smartphone knows, it's the advertising. Free apps show up for two reasons: altruistic programmers that like to share and someone out to make a buck.
I don't have anything against someone making money and using advertising is one way to do that. I even find some ads useful in the same way I have interests in ads that show up on TV and in magazines. Unfortunately, smartphones are a bit smarter, or at least a repository for information that is often more valuable than just eyeballs.
These days smartphones know where you are, who you are talking to and even what other apps you are running. Do you want the world to know that? Or the guy that programmed the neat compass app? Or the unnamed advertiser that gets this information?
The difficult question to answer is who gets this information and what information will they get. I have over a hundred apps on my phone and I doubt that I have read the licenses and releases for a fraction of these. Worse, they can change with each update and updating occurs daily. Even buying an app sometimes just turns off the display of an advertisement. Your information is still going off to never, never land.
So what is a person to do? For now, I'm cutting back on apps and only keeping those I really need or ones that don't ask for the world. What are you doing?