Someone install a modified version of kernel which has u-boot included. This is usually used to start MeeGo/Nemo If you done that and so you have U-Boot, you can boot your phone from SD Card and so you have an hope to recover it without usb cable. To know if you have u-boot is simple. Do you see a pinguing image and various text string during boot process ? If not sorry you don't have u-boot installed