I'm developing internal solutions using WSS 2003 in my company. The
concept is simple, I create lists and nightly synchronize (fill,
update using wss web services) fields in that list with data from our
internal systems of records using the web . Other fields are used for
tracking work flow and statues and they are manually updated.
It works well.

I'm using the datasheet view with success and people like it for its
sorting and filtering capabilities.
I have some calculated fields that produce links to other pages
producing "drill down" effect.

The questions that I have are:
a) Showing images in the Datasheet view:
some of my calculated field links are very long as they include
parameters and I can't figure out a way of showing an abbreviated
link or an image in the datasheet view. I can do it easily using the
HTML based data view but the holy grail will be showing an
hyperlinked image the datasheet view.
The native "attachments" field shows in the datasheet view like a
paper clip and is exactly what I'm looking for.
Is there a way of doing it?

b) Making some fields read-only.
Is it possible to make some fields read-only in the datasheet view?
I have seen it at work when lists have the simple approval turned on
(so there is a way), but I don't know how it is done.