Blender ver 2.5
Change to Edit mode to change the text
Choose F (font) to change fonts, styles, etc.
To load other fonts click here.
Go to C:\Windows\Font select the fonts you wish. (Blender able fonts begin with a capital F)
Note: You can also download fonts to a directory
Click the F to open the menu of fonts
. Choose your font (BFont is the default Blender font)
You can also extrude to create a 3D effect, change the offset, etc.