Module development and code questions

I am developing a new module for Microformats, and so far have managed to complete stage 1.

What it does is when a user creates or updates their profile it takes their $user->email and a custom profile field called profile_homepage, and generates a MicroID hash like this:

Hi,

I have an input field in a form where user have to select a datetime, is there a way to include a calendar (popup?).

regards

This is my work log for Sliding Menu

- Started Dec 1st
- early beta

check it out - http://www.thethisorthat.com/

This hook is very handy, but in practice I see one possibly big problem. The problem is that any module can use this hook to change some form.

So how can I be sure that my changes will be the last to take effect?

Cheers!

I am updating my mailsave module, but the way the form_set_error() function works is giving me a slight problem, so I just want to understand why it is written like it is. I'm sure there's a reason, but I like to know how things work!

I've experimented by simply trying to include Drupal's bootstrap (similar to how it's done in index.php), but it won't work.

Is there any way to include the bootstrap or something similar so that I could use Drupal's functions in an external script?

Thanks in advance,
Matt