How do I center something in PS?

[Conteo]

For example I have just created a quick logo, and have just copied it to a gradiant canvas, how to I center it, I find myself just doing it by eye, but when I look close its off slightly.

Its buggin me.

Thanks.

Screenshot of what I mean...

http://bw-online.co.uk/uploads/spx_file114.jpg

[Toon]

You could select the background and draw rules where the centre items are then you will know, when you click transform on the centre image you will be able to line it up to the guides you have drawn.

[Arkady]

Select the background layer. link the layer you want to center. The Align Icons will become active on the options tool bar. Succesively click horizontal then vertical center. Done.

[Conteo]

What do you mean link the layer? and where do the options apear?

[Arkady]

To link layers:

Select a layer or layer set in the Layers palette.
2. Click in the column you want to link, immediately to the left of the layer name and to the right of the eye icon. A link icon appears in the column.

To unlink layers:

In the Layers palette, click the link icons to remove them.

The tool options toolbar usually appears immediately below the menu bar unless it has been moved elsewhere by the user. It's contents change with each tool change. For example when you have the zoom tool selected, the options toolbar shows buttons like (Fit on Screen), (Actual Pixels), etc.
I did omit to mention previosly, that you need to select the move tool for this procedure

[Alex*]

when you drag your logo onto your gradient canvas hold down shift and drag that will center it in your gradient file

[Conteo]

Okay, thanks guys, I have done it now. : )