Here's a more detailed response based on my experiences in Zürich since arriving in May 2013. I'm 29, with a relatively useless BA, took some German in high school but hadn't spoken it in 12 years.
English/Irish Pubs Really your best bet. Working language in many is English. Many staff start with no German and no bar experience, and some of people working at them don't have great English skills either. As a native speaker (i presume) you have a great chance. Bars gets busier and hire more when the weather gets colder, so now's a great time to be applying. If you have even a bit of German, you can apply at non-English/Irish bars/restaurants too. Lots of staff at them with limited German. My first job here was at the first place I applied (with no experience and limited German). With a bit of experience, I left and got a slightly higher paying job at another bar. Easy, accessible, English speaking.
Pizza Kurier I was a pizza kurier for about a month. At this stage my German was decent. But a 35 year old Italian guy I worked with, arrived 2 months before I started working there with absolutely no German and limited English. He had a great attitude though and tended to get the most tips. People in Zurich understand enough English, or if they don't you can get by with smiles and sign language to do simple stuff like deliver pizza. The working language was swiss german for the most part, but there were quite a few staff with no German and the others just switched to English when necessary. I applied online and heard back a couple months later.. tried it for awhile but quit as I had 3 other jobs at the time. My Italian colleague went to every pizza place he could find in person and got a job within a week. If you have a driver's license and a gps or smartphone, you can do this job.
Bike Courier If you don't have a driver's license you can do this. I did this for 6 months (at two different places) and it was my favourite job. Some courier jobs you need Swiss for, as they talk over the radio telling you where to go and you have to understand, and they have to understand you. (I was fired from this job after a month because of this) Others though you are just given a route in advance with what to pick up and deliver, and absolutely no German is required. Then there's also food delivery by bicycle, which I haven't done. If you like cycling, it's a great job.
Teaching English. I did my Celta in Asia in 2009 and have had a bit of experience since then. I applied everywhere I could find when I first got here but didn't even get a response. Eventually I became friends with a Swiss who did the finances for a language school. This led to an interview / demo lesson as they were 'desperate' to find someone asap as someone unexpectedly quit. The position went to a teacher with more experience, who was friends with another teacher who works there. It was never advertised openly. Unless you have connections, qualifications, a lot of experience and luck, I think teaching English is very hard to break into here. Tutoring is available and not too hard to find through some websites set up for the purpose, but it's really just a bit of pocket money.
Proofreader I haven't done this, but every so often jobs pop up for native English speaking proofreaders. A former colleague from a bar here with no previous experience or specific qualification does this now. Can't say too much about it but these jobs exist.
Temp Agencies Most were completely useless for me. One exception is Staff Finder. Simple jobs like moving tables to set up for a conference are on there, as are all sorts of other temporary jobs. The site is available in English and I think you might find something with them.
Tour Guide I worked as a tour guide, giving tours of Zürich in English. Not a full time job, but a little extra money in my pocket.
Anyways, despite what some may say there are definitely easy, accessible jobs in Zürich for people who don't speak the language or have an in-demand qualification or skill. If you'd like specifics about companies or anything pm me, happy to help.