FeatherySoft has released version 7.0 of Screen Calendar, a Windows 98/Me/NT/2k/XP utility that lets you add PIM like calendar just on any wallpapers.

Screen Calendar really allows you to put the calendar on your desktop wallpaper choosing the calendar size and transparency. Double-click a calendar to schedule your business day. To read your records fully, just move your mouse over the date cell. Also, your records and calendar can be printed. So, your PIM is always at hand (it runs in system tray), but......