you misunderstand the original issue, being that ie blocks any use of window.open(), even in a link. meaning the following is still blocked, and by the default explorer configuration, no less:
[html]<a href="javascript:window.open('newpage.html',params)">[/html]

Are you sure its not your browser settings or something? My example above works perfectly in IE.

:shrug: it didnt work for me and like 10 other people, all on default ie settings (not sure about ie7)

A "better way" to write:
[html]
<a href="javascript:window.open('newpage.html',params)">
[/html]
is:
[html]
<a href="newpage.html" onclick="window.open('newpage.html',params); return false;">[/html]

That way it satisfies both users with and withought JavaScript support on their browser.
(winout JS you wont be able to control the window anyway)

Using href="javascriptsome code)" will also write the returned object to the document window. So you'll get a blank page with "[object]" written in it in IE and in FF you get "[object Window]".

You could wrap the javascript in void() like:

[html]
<a href="javascript:void(window.open('newpage.html',params));">
[/html]

but thats just adding unnecessary code.

I've never had a problem with popup blockers blocking window.open() in an "onclick" event..
On non-interactive events.. like window.onload or setTimeout .. yes.

I've never tries javascript:window.open in the href attribute. Maybe thats handled differently. You should probably try the onclick method, as its more standard.