I just bought the Sony Ericsson Xperia X10 mini pro?

i had that phone, i installed free anti virus www.mylookout.com or i think you can download it free from the market, also download a battery booster i had "android booster" free from the market. and when your not using the internet go into settings and click on "accounts and sync" and turn of/untick background data, then click on "wireless and networks" and scroll down to mobile network and turn off/untick "data traffic" it saves alot of battery, plus keep bluetooth and wi fi off when not in use. i also downloaded from the market OI file manager, good for creating folders and moving pictures/videos/music into folders. and i also downloaded mini opera browser, very fast. hope some of this is some use to you. enjoy your phone -)