DNS, 1983, and dependent advances like email host resolution via MX records instead of bang-paths. *shudder*
Zeroconf working on top of DNS, 2000. I plug my printer into the network and my laptop sees it. I start a web server on the network and my browser sees it. (Assuming they broadcast their availability.)
NTP (1985) based on Marzullo's algorithm (1984). Accurate time over jittery networks.
The mouse scroll wheel, 1995. Using mice without it feels so primitive. And no, it's not something that Engelbart's team thought of and forgot to mention. At least not when I asked someone who was on the team at the time. (It was at some Engelbart event in 1998 or so. I got to handle one of the first mice.)
Unicode, 1987, and its dependent advances for different types of encoding, normalization, bidirectional text, etc.
Yes, it's pretty common for people to use all 5 of these every day.
Are these "really new ideas?" After all, there were mice, there were character encodings, there was network timekeeping. Tell me how I can distinguish between "new" and "really new" and I'll answer that one for you. My intuition says that these are new enough.
In smaller domains there are easily more recent advances. In bioinformatics, for example, Smith-Waterman (1981) and more especially BLAST (1990) effectively make the field possible. But it sounds like you're asking for ideas which are very broad across the entire field of computing, and the low-hanging fruit gets picked first. Thus is it always with a new field.