I left my power cord at work

A USB port supplies 5v at 1amp

If you only draw 500ma off there is a chance that the voltage will go up to 6v

Not a killer if it wants 5v but you will cook the phone if it only needs 3.7v

Some phones will only accept 3.7v (Some Nokia units)

Look at the phone battery and it will tell you what it needs

A USB port puts out 500ma, and will charge your phone perfectly fine and will NOT damage the phone. That is the way I charge all my phones. The statement that if you don't utilize the ports full voltage potential (5v.) that it will raise the voltage is not true. I am an Electrical Engineer and that is simply not possible and 5v. will not hurt your 3.7v. battery, otherwise most 3.7v phones wouldn't come with a USB charger, right? The power supply of the computer regulates the voltage, you can only DROP voltage if you EXCEED 500ma. Hope this helps, and charge away!

palm centro hotsync cable will charge the phone but more slowly than a wall or car charger,