Run Iceweasel 4 On Squeeze

Go to http://mozilla.debian.net/ and just follow the instructions....
I was only a bit reluctant because libcairo2 had to be upgraded from version 1.8.10-6 ( stable ) to version 1.10.2-1.1~bpo60+1 ( squeeze-backports ). I use a patched version of libcairo2 : http://debian-bits-and-snips.blogspot.com/2011/03/improved-font-rendering-with-lcd-filter.html , but apparently you don't need to patch libcairo2 any more....

Still needed are these lines in ~/.fonts.conf :

<!-- lcdnone, lcddefault, lcdlight, lcdlegacy -->
<match target="font">
<edit mode="assign" name="lcdfilter">
<const>lcddefault</const>
</edit>
</match>

The menu fonts were too tiny so I had to add a userChrome.css with :

/* Global UI font */
* { font-size: 11pt !important;
font-family: Candara !important;
}