Use the detour.
In Keynote add an object.
Make the object transparent: no border, no background, no shade.
Click inside and type }
Apply a font, color and size (Cmd-T)
Click outside the object and then select it.
Copy it.
Open Preview.app.
Type Cmd-N
Type Cmd-C
Go to Keynote
Type Cmd-V
You now have the character as an object you can resize.
Pratice with other object/character settings to get the desired result.
Alternatively, you can create a EPS or Tiff object in an external image editor. I use PhotoShop Elements 2.0.