Module development and code questions

I am writing a module right now that changes the theme. This is a site specific module, so the only two themes are a "high bandwidth" theme and a "low-bandwidth" theme.

On each page I am generating a link back to that page that allows the theme to switch. For example. if you were at mysite.com/about, then there would be a link a to mysite.com/lo/about, which when you click on it, the theme changes to the low bandwidth version.

I am in the process of writing a module that will take a date as part of creating a node. If there were a form_date() function, I would use that. Because there isn't, I'm here asking for advice.

What is the best and most consistent way to create a date entry on a form?

Thanks for your help!

Has anyone got the gallery.module working with Drupal 4.6.2?

When I try I get a blank page at mysite/gallery.

My local task menu items seem to be alphabetizing themselves rather than appearing in an order I add them. Is there any way to override this? How?

Error - "the document contains no data" when i try to attach a file or image.

Centos(linux)
Apache2
MySQL 3.23.58
drupal 4.6.2
upload.module

These forum topics are related but have no solutions -
http://drupal.org/node/19132
http://drupal.org/node/25835
http://drupal.org/node/20788

Is there anyway to get Trip Search to pass the variables in the URL ala Google or even the Drupal search so that its easy for users to go back to a search later.