I would give people the option of making a token donation to FT to disable ads. At home I use an ad blocker but at work I'm not allowed to install this rather useful bit of software.

I would also kill the mobile site or vastly increase its usability. Navigating the traditional site is easy. Navigating the mobile site is hard. For now, there is no utility (for me) to even bother with the mobile site. When my iPhone / iPad goes to the mobile site, I immediately switch to the full site.

I would find a way to post pics. Uploading to flickr or similar then linking in is painfully time-consuming. I'd rather just embed the pics directly into my posts. I suspect the difficulty in linking in pics is the reason relatively few posts have pics in them.