Blimey wouldn't use an Android unless very careful with what applications I had loaded on Great phones and some great apps but very much like the PC world with mucho malware floating around due to the way the App stores are open to all. Part of its success but also a big issue it seems.
I guess depends on the way the application is created if its not holding any of your banking details locally its probably as save as ringing up in a street or public place a slight risk but hardly the biggest of risks.
Of course Google and Apple yesterday took a bashing due to the way they retain the location data for periods of time up to a year in the case of Apple on its Iphones which have location services activated..
Also found the Wifes up to date firmware Ipod touch has been affected by malware and when researching found its a massive problem I thought apples were malware proof!!!
I'd be careful with your PC while out in Phil Kids out there go nuts when they see a Laptop and start watching films and use flash games websites as a rule all major malware sources it appears