I wondered how you can best take a good picture and modify it so it fits into the Mb rating of many forums, directories, etc. I've been having problems getting a result I like. Is there are program you can recommend? Or this there a procedure I should follow?
do you have any image SW? most of the time programs will let you resize the pictures for the web, (generally < = 800x600) and adjust the JPG compression ratio. you can do this with Photoshop obviously but most other programs as well.
If you have a lot of photos for filesize reducing, you can use the online batch photo resizing tool on my blog. I develop it because many free web hosting spaces have a 500k filesize limit. It's easier than using photoshop to adjust images one by one. Users specify a filesize threshold, the program will automatically decrease JPEG quality gradually until filesize below the threshold or jpeg quality below 0.75. After that, the program will automatically reduce the image dimension gradually until filesize below threshold. The page is: http://freejtv.blogspot.com/2007/05/filesize-reduction-for-jpeg-image.html
In Photoshop, File > Save for web and then choose the compression you like (I use between 80% and 100% mostly). This will decrease your filesize with almost no quality changes. But as timsdd said, there are other programs which let you do something like this, so If you don't own a copy of Photoshop you don't have to buy it for that, just use any other (and cheaper) alternative.
PS is pretty slick b/c it has a built it script/batch just to resize photos File > Scripts > Image Processor and then you can select jpg, tif, the amt of compression you want for the jpg from 1-12, 12 being least compression (max file size). You can even run a script (like © watermarking). But by the same token not everyone has it, stevpan's online option looks intriguing
The batch image resizer has been moved to http://slideplay.blogspot.com/2007/05/filesize-reduction-for-jpeg-image.html