This topic was discussed recently. You can find a lot of ideas on how to track your projects in this thread.
http://www.blackhatworld.com/blackh...o-you-manage-all-your-sites-accounts-etc.html
A bit difference. That post discuss manage accounts, which could be easily end up with Roboform.
This post has the question of "management"
Actually the other thread
is about "management".
The question in that thread is what's a good way to manage all the data for all your different websites and other IM projects. I don't see the major difference between that question and yours.
You may be able to gather more information in this current thread, but so far there is more info in the other thread.
Managing all this data is the foundation of managing your business. Some people have worked out pretty simple methods to manage all their different projects. Scheduling and tracking all aspects including accounts, websites, backlink urls, keywords, opportunities, etc.
When you read through that other thread, just skip the replies that only talk about roboform and you might be able to get some good ideas. Some of the responses are about accounts and passwords specifically, but there are also many other replies about managing all aspects of the work, including SEO projects such as you're interested in.
The most common method mentioned is to use standard business management tools such as spreadsheets, and then organizing all the individual projects into seperated folders, but there were a few other suggestions as well.