edit:
I found a solution for the problem:
Download the Photoshop pack of Subsilver theme from
http://www.phpbb.com/downloads.php#subSilver
Open up the phpBB2 subSilver SDK.psd and along with the picture you need the text for. Now use the Type-tool (T) and edit one of the text layers in the phpBB2 subSilver SDK.psd. Now copy&paste the text you edited to your picture and vóila! We have a button with the same font as used in the phpbb2.
[flash=,]http://img96.imageshack.us/img96/8306/ohjefontti5aa.th.jpg[/flash]
Other way is to check the layer properties for the text layers, and then save them as a new style layer. This way you can quickly add the text many times with the same properties.
edit2: I was a bit hasty with the last edit. You have to change the mode of the image to rgb of course if you want to add the layers

. And the font is arial with strong attribute and with some blending-properties, but in most of the cases the users won't notice if the layers properties have been added or not.