Straightforward power supply/transformer-- 110v -> 3v, 3.

Hello. I have done a little electronics tinkering but it was years ago and I've forgotten most of it-- recently I was pricing AC/DC converters for my old digital camera (it didn't come with one) and they cost much more than I'm prepared to pay. How difficult would it be to construct one? The DC output is an odd voltage (3.4v), and I can't seem to find a non-Epson one with similar voltage. Multiple outputs would be really handy as well, as I could easily use 3v, 6v, or other settings.

Any suggestions, such as links or books to check out would be really helpful. I did some web searches but the results were either too broad or specific to projects which were markedly different than what I'm looking for.

Thanks
Paul

because i forgot

It requires 2.5A out. I also just found the power supply project in the "projects" section (of all places) and it looks like it might be a little more than I need. Maybe I ought to make it anyway?

Cheers
p