Hmm.. I still use blog and some web 2.0 sites, I still find them very useful, well at least for me. I don't do guest posting and wikis, and I already stop using web directories for a long time now.
Yes start with the top Web 2.0 sites as they are free and easy to make. Then do the top Wikis and blogs in your niche. Then try to get guest posts and T1 links through link exchange or other method as related links are working still 100%.