As individuals, we benefit from being in control of our computers. To maintain that control, good security is essential. So I'd say work on that, specifically o

As individuals, we benefit from being in control of our computers. To maintain that control, good security is essential. So I'd say work on that, specifically on sandboxing and limiting the damage untrusted or compromised programs can do, re-writing crucial programs in languages immune to as many exploitable bugs as possible, maybe even try formal verification (for small but essential code, like OS kernels or filesystems), if you're feeling ambitious.