What size image should I use for BlackBerry context menus?

The BB OS 5.0 supports images for context menus. The API documentation says the image will be scaled to fit a square set by the height of the menu font. I find that totally unhelpful.

The only way I can explain that method of calculation is due to开发者_高级运维 screen resolution and DPI. But since the 5.0 OS is only valid on a handful of devices with similar screen sizes, I reckon they can specify the actual icon size they use.

I'd like to choose an icon size that's closest to the default menu font height so that the they look OK.

What size do you use? Do you even use this feature?

I haven't used it yet, but I would recommend using any square ratio maybe up to 64x64; the problem is that with new devices on the horizon (eg rumored tablet - with much bigger display) it won't necessarily be practical to target a specific screen size.