Zx-81 from our forums has just updated his HP48 Calculator Emulator for the PSP. It emulates a pretty expensive calculator on your PSP for free. What has changed since the PSPX48 v1.0.4? According to Zx:
* Add new beautiful icons and background designed by Jer666
* New user interface with menus and usefull options
* Display battery usage
* Add Help window with all PSP shortkeys
* Save configuration file option
* Screenshot image option
* PNG images instead of BMP (smaller images)
* Toogle between analog and digital pad option
* New keyboard handler and new mapping
You will need to get the HP 48GX Revision K ROM from hpcalc.org. We can't host that file, but it's easy to get from there (look for the link in the article for this file at pspupdates.qj.net). There's also Zx HP48 documentation for those who need it and even has a way for you to add two more slots of memory to your HP48 (again, look for the links in the article on PSPX48 v1.0.5 at pspupdates.qj.net).