I would suggest pre-caching the conversion results for a bunch of popular sites. Grab the Alexa top 1000 or something. Basically, I can understand why my random site takes a little longer, but not big, fast, popular sites.
bwh2: Great idea. My question is: Would it be kosher to pre-cache? ;)
There is a powerful caching module for the sites you access from your mobile phone though. I will have to ask my developers how to implement this in the preview.
