When you are editing ASPX pages using the Design view, if you press the
Enter key, it inserts <p></p> tags, but if you only want a <br>, press
Shift+Enter instead.

Since panels are containers, if you make a panel invisible, I would expect
everything it contained to be invisible as well.

For maximum control of your HTML, it is much better to code it directly in
the HTML view, rather than the Design view. The behavior of the editor and
its reparsing of HTML is annoying. Microsoft representatives have said that
it will be corrected in the next version of VS.NET.

Having used Microsoft Frontpage quite a bit, I would prefer that the next
version behaved more like Frontpage. Specifically, when switching from the
Design to HTML views, I would like the cursor position in the HTML view to
be placed where the cursor was in Design view, or if I had something
selected, I would like the corresponding HTML to be selected when I switched
to HTML mode.