the problem with jpg and batch is that you need to create an action for it to work. its quite simple tho..
from what I understand you already have a folder with the tif files.. open one of those files on photoshop and go to the actions pallete. With the image opened, click on the create new action, give it a name, and it will start to record automatically...
Go to file > save as and choose jpg, and choose the folder where you have the tif files. save the image without changing the name of the file.. then go to file > close.
then click the stop button on the action pallete. You should have only 2 steps on the action. "Save" and "Close"...
Then go to file > automate > batch.. on the batch options windows:
Set: Default actions set (this is the set where you kept the action you just recorded)
Action: choose the action that you just recorded from the list..if you dont see it, you are in the wrong action set..
Source: Folder (then click on choose and find the folder with the tif files)
you can leave all the other options unchecked.. make sure you leave "override action open commands" unchecked..you are going to run the batch on a folder, not on already opened files
Destination type: Folder (then click on choose again and selected the same folder with the tif files)
then make sure you check the "Override Action Save As Commands"
"File naming" should be left as is to get the result you described.. (just leave with the "Document name" on the first field and "extension" on the second field)
Here is where you can choose a path for the log file in case you run into errors during the batch..
then just click OK to run the action and thats it...
if using CS... download Dr. Brown's Image Processor from Adobe Exchange
Richard M. Harrington, PMP
Author: Photoshop CS for Nonlinear Editors
Co-Author Final Cut Pro on the Spot, After Effects on the Spot, Broadcast Graphics on the Spot, and After Effects @ Work
Check out the new DVD: Photoshop CS: Essentials for Digital Video from http://www.photoshopforvideo.com