For general thoughts on cool tech stuff, I find it fruitful to follow smart individuals rather than magazine-type sites.
Jim Gettys' blog is thought provoking, even if you're not working in the same area as him he's a brilliant techie and lucid author. But it updates infrequently.
Keith Packard's is also decent.
Rob Pike's is more scattershot but occasionally fascinating. The
Computational Complexity blog is more esoteric but sometimes has good mind-benders.
Dan Lemire has some good stuff at times. The
editor's letters to the ACM span a range of topics, some boring but some great.
Lambda the Ultimate and Slashdot have down hill but I still scan there for more general-public tech news/major releases/etc.
For keeping up skills, I find more specific newsgroups and sites to be much better than general-purpose ones. I change what I frequent based on what I'm most interested in at the time. The LKML, comp.lang.c.moderated, comp.unix.programmer, and comp.lang.python are generally in the mix.