The first trend that I am trying to keep on top of:

(Perfection is the enemy of completion. Structure should be inferred, not imposed.)

There are two big things on the web that are undergoing sea changes. The second is the web platform and web design ideology. (I would have loved to be @ Web 2.0.)

FIRSTLY, the continual evolution of the way in which we use the web to communicate, organise, co-operate, and collaborate. The biggest firework in the box is the blog, but this is just one example of a trend that is exemplified by lean, fast user interfaces, attention to information architecture, accessibility, utility. Deli.cio.us, Meetup, GMail, Flickr, etc. Google, of course.

Aspects of related trends include the whole GTD phenomenon, and software like Quicksilver, things like wifi, etc. What these prove are:

(a) That this not just a net-related phenom, but a true change in the way people work and interact
(b) That next-level UI is coming from Geeks hacking neat code on UNIX-based platforms. Duh. (see also: dashboard)

Also, this is a big social thing. Trust, authority, organisation (as per Buzzmachine).