Don't start the party without me!
So you think customization and functionality can be done just as good on iOS as it is on Android? Think again bro. I've been on the jailbreaking scene long enough to admit that Google's implementation is far superior and more flexible stock than what iOS can offer when jailbroken.
1. Complete file access to the Android subsystems
I do know that iOS has apps that let you peek what's under the hood as well as using SSH for it (root/alpine FTW) but Android does this baked-in with a file manager. Once rooted, you can actually make edits to each individual file and actually make it do something on the phone - For example, edit values to control how HSPA+ works on the phone or configure the phone to render the screen.
Apps specifically designed for rooted users allow for greater functionality such as taking control of the display driver and making changes to the recovery image. This is where stuff like ROM Manager come into play; these basically allow you to do complete ROM backups on the fly, configure Dalvik Cache and even dual-boot to a different ROM - say MIUI and CM7.
2. Robust widget system
Though there are iOS alternatives and workaroungs, things such as SBSettings, etc. has nothing on real Android widgets. Any kind of widget on ANdroid is configurable down to the last font size, x/y position, color alpha channel and layering. Try apps like mClock and BeWeather, and see what I mean.
Also, these widgets can do a lot more than just aggregating news or displaying the weather; you can set them up to do specific tasks such as open an app (whether relevant or not) or send a message, invoke a function on the phone, etc.
3. Native codec playback
Android has more powerful in-house media options such as support for different codecs (MKV, FLAC, OGG, etc.) and even plays native 720p/1080p content without conversion provided the correct hardware. Players can switch to software or hardware acceleration during playback, and some apps can support subtitles and different audio tracks depending on the file. Hell, the built-in equalizer is way better than the presets on my old iPhone.
4. Integrated sharing options
Called Intents, this is an Android feature that any app can use to call/invoke functions from other apps. This is the most useful in sharing content; for example, a picture in the Gallery can be shared through any of the installed apps that could perform such tasks such as Dropbox. So basically, interoperability of apps is present and makes file transfer much easier. An article from Feedly or Pulse can be mailed to somebody via Gmail, or a YouTube video's link can be encoded as a QR code without manually launching an app.Edited by jjsoviet - 10/22/11 at 1:05pm