For the most part, my social events and standing obligations have stayed on a Google calendar synced with iCal, but for more specialized, shorter-term projects, I've begun using PocketMods, printable calendars that fold into small booklets.
Printable calendars are certainly nothing new, but I like the simplicity of the PocketMod layouts, and they offer a wide variety of templates, which means that you don't have to comb multiple sites for the templates you need, and you can customize your booklet by combining multiple templates. For example, if you happen to a musician who loves al fresco dining, you're in luck, since you can build a booklet with blank music staffs, a weekly weather guide, and a tip table.
Personally, I've used them to block my work assignments off into small, single-calendar chunks. I keep my PocketMods localized with specific work materials: one with my teaching stuff for daily reading assignments, one with my dissertation research for daily writing goals, and one with freelance writing materials to keep track of ideas. Having them separated makes the tasks feel much more do-able, and instead of staring at a calendar with three or four potential tasks, I only have to face one at a time.
It's simple, but it's been really effective for me. If you don't have a method that works, I'd suggest giving PocketMods a try. And if you do have a method, are there any tools that have worked for you that you'd like to share?