This product is a life-saver!
Let's take a quick look at the pros:
1) It's cheap. Really, just over a tenner for a backup battery for your iPhone. Perfect!
2) It's easy to use - just plug it in to your iPhone charger. The indicator lights show when it's charged.
3) It looks cool-ish. Ok, so it's not as gorgeous as your iPhone, but it's not bad. It's certainly not ugly.
4) It works beautifully. Just plug it in to your iPhone - it charges and powers the phone perfectly.
5) It's small. Charge it, then drop it in your bag/pocket. Forget about it. Remember it when you need it.
And the cons:
1) You can't charge both the iPhone and the charger at the SAME time. Not that big a con.
2) There is no real support for the charger when plugged in to the iPhone, so you'll need to hold it carefully or put it flat on a table.
That's about it! The pros certainly outweigh the cons, and ... it's cheap! It works, and has saved my bacon on numerous occasions. You're out for the day, need your phone for lots and lots of things (making calls, sending texts, surfing the web, checking email, playing games, listening to music, watching a movie etc.). Half-way through the day, your battery's looking tired - no worries, pop this little baby in, stick the phone in your bag and get on with something else. Come back later, phone recharged!
Would I buy another? I did. For my sister, when she got her iPhone. I hope that's recommendation enough.