If you run firefox in both you can simply add the foxmarks extension in
both windows and Linux. import the firefox to ie I suppose.

I ran Firefox in Windows in the end( I had been having weird problems
with Internet Explorer anyway) and kept the profile for both Ubuntu
and Windows on the data partition I share between the two OS's. Works
great! If anyone else is interested see also
www.mozilla.org/support/firefox/profile#move

I have a pc which dual boots Ubuntu Feisty and Windows
XP.
--The partitions are arranged as follows:
--1 Windows XP (also visible from Ubuntu)
--2 (My) Documents (visible from XP and Ubuntu)
--3 Ubuntu (not visible from XP)
--4 Ubuntu Swap

--a) I want to be able to create a common pool of "Favorites" from
--Internet Explorer with "Bookmarks" from Firefox 2 0 0 3. What is
the
--easiest way of doing this please someone? The idea is that I have
--always have the most up to date list whether I booted in Windows
or
--Ubuntu.

Have you looked into an online favorites pool like del.icio.us or
google bookmarks ? There are several online based apps and sites,
all free, to sycronize your favorites no matter what platform,
through Firefox or IE. Don't know if that's something you would be
interested in. Firefox has plenty of plug-in for these apps.

In the version of Foxfire I'm using, 1.5.0.11, click "File/Import" and
a dialog for importing IE "Options, Bookmarks, History, Passwords and
other data" appears.

Don't know how well it works. And know nothing about importing in IE.