Module development and code questions

I am developing a new module, along with a new node type. When creating a new node, I would like two of the values to be driven from comboboxes...easy right? Trick is, I want one combo box to drive the content of the next combobox. I have all of the values, and the relationships in database tables.

Any ideas or suggestions on the best way to do this in a Drupal form when a node is created?

Thanks!

hello folks, i'd like to find out about creating containers for groups by category with the Organic Groups module and am wondering if anybody has done this...

for example, if you've got tons of users, and then (hypothetically) hundreds of groups, would it be possible to generate 'categories' for the groups to be assigned to - with the ability to assign the same group to more than one category just like other nodes in drupal? for example: imagine a bunch of groups that are fan clubs (just an example, NOT what i'm doing):

current group listings include:

So I saw the example block in the handbook but have a question about it.

I made a block to list the recent files uploaded to my site, however because the title is very long (over 25 characters -- usually around 50-60 characters) the side bar the block is in becomes deformed one way or another and I've traced it to this problem specifically.

So before I made a special function to truncate the title to 25 characters I was wondering if there was one in drupal or different solution to this problem.

In my new module I've created a page with a callback like module_callback() and in most circumstances this trick has been working when combined with the relevant menu items. However I'm now trying to implement local tasks to a single callback like those on a node with urls of the format ?q=module/pagename/[id]/localtask etc.

I searched the PHP documentation before posting. What exactly does the t('string') function do? I couldn't find it in the PHP Docs and it is used extensively in the Drupal code.

Thanks.

I have a module which inserts fields into the registeration form the hook_user(). I am however finding the data always ends up in the table. Anyone have any ideas as how to make it not save any of the data in the user table from the specific hook implementation?