If you run certain scripts - let's say repeated queries to the same site - you want to make sure your protect you SERVER IP so it does not get blocked. Which software or service did you find most useful for this purpose?
Perhaps if you were more specific, you could be helped. I remember when someone managed to extract the code from the google toolbar that allows it to query google for pr, the code was everywhere ( and still is ), only it worked nowhere because google blocked you when you smashed thier servers ( they do this with language_tools aswell ), the way around it in this case was to use multiple servers to get results from, like all thier different ips for toolbars and country specific sites. The reason the code doesn't work anymore is different, they changed thier api and whatever and it just broke, it still works if you use it on localhost but not on the net, can't work it out, I'm not trying too though, just using that as an example of a way around what you're experiencing. Without knowing the code your using or at least the service, it'll be hard for anyone to give you any real help.
Let's say you wanted to do a ranking check - seoadministrator-type - and query Google for the first 10 positions to grab URL's and Description Tag. What would you use?
What language are you building it in? I would write an array of proxies, then build a randomizer that sets the proxy. Do a check if the proxy works: If it doesn't then pop it off the array, if it does set the proxy, and do your web-scrape.