Smartphones are for city use... soo... you usualy u'd have a charging spot within 12h spam... soo don't think its necessairy...

I think extended batteries are worth a look but not necessarily for everyone. I currently use my stock battery but have wireless charging stations at my desks at work and home which keep me going throughout the day, especially at work where our data center is a cell signal black hole.

Yes, I put a 2000mah battery in my sammy g2 (it comes with ~1600mah battery).
The battery came with a custom back cover that makes the phone only a teensy bit thicker.

My stock battery is sitting in a corner as a backup.

I am not constantly on my phone, dont use animated wallpapers & don't leave the wifi running so I get about 2-3 weeks to a charge. With heavier usage & wifi use I think I can eek out about couple days.

A point to the Apple fans out there:

WE ANDROID USERS CAN CHANGE OUR BATTERIES!! BWAHAHAHAHA!

After hearing what Rodney had to say, I looked into getting one for my phone (LG G2x) since it barely lasts from 7am to midnight. I found this one on Amazon. It even comes with a dual wall charger and a back cover all for $15!

to bad the stupid Iphone dosnt let you replace the battery. I cant complain to much though sine its my work phone and they pay for it.

I would love to have a extended battery for my ONE X but i can't find any that can fit on my phone :-(

I had an extended battery for my old HTC Desire Z, it was great
Bought a Galaxy S3 now, don't have an extended battery because I carry in my pocket a universal USB battery which I can use to charge my phone, laptop and tablet. :)

I'm still rocking the stock 1500mAh battery on my Evo 4G, and I get between 10-32 hours battery. Why? Because when my phone is idle, it's actually idle and not getting updates on FB, Twitter, and a whole bunch of unnecessary data transfers. And I listen to about 4 hours of music on my phone per day.

I have a Samsung Galaxy S2 but have not got a extended battery yet, its on my to do list.
I do not have the problem so often that my battery runs out on me.
I have rooted the phone and tweaked the router and such, so I can have the brightness at full blast.

Cheers

No, the battery in my N8 already lasts a pretty long time. I can be playing music on it and using sat nav and it lasts all day

hmm i dont think so i cant change battery on my HTC ONE x