When we first reviewed Siri last February, we called it "one of the most ambitious mobile services we have seen in the last few years." At the time, we acknowledged that, while Siri - which was recently acquired by Apple - has answers for a plethora of questions, it wouldn't be able to handle them all. We lamented that "sadly the app doesn't use Wolfram Alpha to give you answers to factual questions (yet)."

Today, we lament no longer, as the latest update to the virtual personal assistant notes that it can now provide you with "more knowledge and computation results" using "computational knowledge engine" Wolfram Alpha.

We first ran into Siri nearly two years ago now and since then the company has been on a tear. During this year's SXSW Interactive, we quickly pegged it to run away with the BizSpark Accelerator competition and soon after it was acquired by Apple. Now, a partnership with Wolfram Alpha can really bring Siri to the next level.

Before now, Siri was limited to a select number of categories and information types that it could answer questions or provide services for. It could reserve you a table for two at a local steak house using OpenTable. It could help you buy tickets to a five o'clock showing with MovieTickets.com or tell you if it was going to rain tomorrow using WeatherBug. But questions like "What time is it in Paris?" or "When was President Obama born?" would likely end up with a list of search results.

Now, with Wolfram Alpha, you'll get a straightforward answer. You'll not only find out that President Obama was born on Friday, August 4, 1961, but that this was 48 years, 11 months and 4 days ago. Or more specifically, it was 17,870 days ago on the 216th day of 1961. (You have to love that special brand of Wolfram Alpha answer, where you not only get the basic facts, but the facts in every way you could possibly want.)

While the app told us that we were "stretching its capabilities" when we asked it "What's the circumference of the Earth?", it quickly answered, using Wolfram Alpha, that the Earth's equatorial circumference was 24,901.47 miles. Where before we relied on Siri to ask simple questions about a specific set of real life situations, we now feel comfortable asking it the most inane of questions. The addition of Wolfram Alpha turns Siri into much more than simply a virtual personal assistant. It's now a virtual personal researcher, too.

As Siri CEO Dag Kittlaus once told us, Siri really is the "mother of all mashups."