I previously used Zirtual for a few months, and really loved it (but my cash flow was very limited so I had to cancel it). The company has since imploded, so I'm hesitant to hire them again. Do you have any recommendations for alternatives? I am looking for US-based, and higher quality (not just someone to book meetings but also someone who can do research, create spreadsheets, create letters based on a template but that need to be customized, etc). Any recommendations?
I see you have already gotten quite a few responses here, and so I am going to make a pitch for Worldwide101, which is the virtual assistant company I founded back in 2009. Our team is US based, and we provide "business grade" virtual assistants - so in essence "more than basic admin" and "high quality", which seems to be what you are after. Here is a link to our website http://worldwide101.com/
If you are interested, I would love to find out a bit more about your requirements so we can suggest a VA for you. You can also check out objective VA company reviews on this site http://www.virtualassistantassistant.com/
All the best,