Hi DavidR,
Well I have been using the Flock browser from the days it became available for download with the Web 2.0 features included. Played around with it, joined their security list. I introduced GetElementsbyClassName.js in the components folder, posted the code at Mozilla's (you will find it inside the regular FF 2.0.3 now). Incorporated some new security in the anti-phishing line, that will come in with FF 3.0 already there. Went through all that was available on "The Burning Edge" and took some patches that were appealing to me security wise. My personal PocketFlock version 0.7.12 now weighs 107 MB and 127 MB on the 1 GB USB stick.
I think mine is as secure as the latest FF build through security enhancing extensions, like NoScript, McAfeeSiteAdvisor, TrustWatch Search Extension, Scandoo, JS view, Cookie Editor, ABP Plus with the G-Updater, ABP Element, AdBlock Learner, Hiding Helper, Stealther, ShowIP, Netcraft toolbar, Clear Private Data, FEBE, TrackMeNot, HttProxy, DrWeb's hyperlink av-checker. Did not have any problems.
I use this browser from a normal user account with SafeXP installed, Avast Webshield inside. So why the cold water fear. I know why I should not have Alexa there, why I do not use Start Stumbling, but if I checked the links I am not afraid of YouTube (now Google) or watch it in Democracy Player (also Mozilla).
polonus