A Better Finder Attributes ($14.95) allows you to change file and photo dates and times, as well as other usefull file attributes that the Finder won’t let you touch. 
It is a great help for digital camera owners who wish to compensate for incorrectly set camera clocks or for timezone differences, web masters, CD or DVD disk authors, graphic arts practioners and software developers.
Personally since I bought my first Mac in January 2006 I think the only aspect that has continually disappointed me has been the Finder. Sure, compared to explorer in Windows it is significantly better, but when stacked up against the rest of OS X and the wealth of great apps around I find it very weak. As such I am always on the look out for apps that will improve it. My suspicion is that Leopard will be a huge improvement, and I have a view that the guys over at PublicSpace may share that view as they have recently reduced the price, BUT that shouldn’t stop you from taking a look at BFA.
It is probably only relevant for a niche market – digital camera, different time zones etc but if you fit into that category (and I do) then I think you will find it very useful and easy to use.
Also included are A Better Finder Rename, A Better Finder Launcher, and A Better Finder Select all of which improve the way you can access and launch your applications, filter files in the Finder, and rename EXIF and MP3 files. A useful guide on where they are and where they are going with the applications is provided by the developer.
So if you want to:
* modify the date and time
* create the date and time
* batch adjust the Exchangeable Image File (EXIF) time & date that JPEG pictures were shot to compensate for timezones or incorrectly set camera clocks
* set the file creation date to the time that a digital camera picture was taken
* lock or unlock the file (prevents the name and the contents of the file to be modified.
* set the Mac OS 9-style creator & type codes, or
* show or hide the file extension for particular files
this will be well worth you taking a look.
A Better Finder Attributes | Chris Marshall – just great!