That being said, I'm presuming you're doing sysadmin under a *nix environment. Sysadmining a Windows box is just brutal.
Email is the bane of my existence. Most of the proposed email deluge handling systems advocate dealing with email for set time periods. This is fine, as a personal thing, but my time with email is mostly spent spinning wheels because I am waiting for a reply to something I need. I don't want those people dealing with email in set time periods, I want the information now! I want their workflow to be severely impacted :)
Which then leads to the necessity of phone calls, which is an even greater time sink.
I ended up resolving to just walk to the person's office if its < 15 minutes and treat it as a keyboard break. Now I'm back in grad school and work from home a lot, so I'm back to waiting for emails again.
In the end I just stopped going. For the most part I was one of many people invited who didn't truly need to be there. Sometimes people will turn up at my desk 5 min prior to remind me in which case I figure I should go - and usually that's a nice indicator.
I still go to ones I need to go, but I've gotten better about asking at the very beginning of what the purpose of the meeting is and what we need to resolve in the next 30 or 60 minutes.
It's a big help and saved me 2 days per week aprox.
I also stopped checking voicemail about 2 years ago and don't answer the phone. That helped a small bit and people know to reach me on IM or email.
It does occasionally lead to an epiphany of the "aha, my problem is exactly [this]!" variety, so sometimes it works.
Sysadmin work is also really horrible, though I would say it's unneeded these days with the help of services like Heroku.
The main time waster for me is being told to "maintain" a system instead of refactoring it. A great example is a recent project I've finished up. Years were spent trying to create bandaids for major design deficiencies. They never solved the problem since there were fundamental design flaws. It was slow. It produced only somewhat useful results. It required lots of time and effort for maintenance.
After much hemming and hawing (and the reality that the system hadn't delivered its expected value after 3 years) I was given the green light to rewrite it. I spent a month validating the design, and 2 1/2 months rewriting it and putting it into production alongside the existing parallel system. The new old system will be turned off in 2 or 3 weeks.
Benefits?
* It produces correct results for downstream apps. This item alone made the effort worthwhile. Everything else is simply gravy.
* As a result of the first item, we now have reverse engineered another vendor's feed with uncanny accurcy. We can now "front-run" them, reducing our latency to act in the market. We can also cancel a subscription that has a $200,000/yr price tag. We can also decommission that system freeing up hardware.
* The time is takes to load new data from the vendor was reduced from 50 minutes to 4. It now scales perfectly linear with new data volume, instead of ever-increasing over time. It can also still be faster (down to ~3 minutes), but those improvements need to be made by another group.
* Since its faster, and has very little overhead, the server has gone from burdened to idle. We can now have other systems take advantage of this great hardware (16-core, 64GB of memory, FusionIO scratch space, very fast SAN hardware).
* The storage footprint of the data warehouse was reduced by 50%.
* On top of the storage reduction, replication to our disaster recovery site was reduced by an additional 70% (on top of the initial 50% from reduced data volume) because of how the data is structured.
* Source code reduction? 85% fewer lines. It is now ruthlessly simple.
* Maintenance? It now auto-recovers. Untrained operations staff just perform 2 automated steps to recover from 99% of problems that we expect to occur in production.
:set autochdir