If you use Xrumer on your whitehat website you run the risk of getting banned for getting to many backlinks in a short time. Use these tools on portals or web 2.0 properties to boost their ranking and PR and then link to your site from these.
illegal? Like what u worried about prison or getting banned?
No its not illegal but it could get ur site banned from google from search traffic, so do what Given said and u will be fine make a couple of blogs or splash pages on a different Domains and pound those and just link to your site from them, Dont use the same IP though use different server IPs if u do the Domain thing.