Cellboost is a tiny disposable battery charger that is available for all the major brands of phones. It's a great solution for frequent travelers or even just the absent minded. Since it's portable, you don't have to be near an outlet to charge. For optimum mobility, you can also talk on the phone while it's being charged.
While one Cellboost is rated for up to 60 minutes of talk time, we tested one with a Sony Ericsson K700i (a phone not known for good battery life) and got 193 minutes of usage. While the results will vary, three times the suggested maximum life span was a big surprise. Even with 60 minutes of talk time a Cellboost is great to have tucked in your travel bag--but with over three hours of talk time you're never going to find our suitcase without one.
Price: around $10
Where to buy: Wal-Mart, Staples, Office Depot, online