办英国签证是最好有回美国的有效签证。当时她问我一下是不是还有回美国签证， 我说我去中国办 （而且我有从英国到中国的机票），就通过了。 不过英国领事馆有一点好处，收visa和master信用卡， cash也不用exact change. 纽约英国领事馆网站在http://www.britainusa.com/visas/YesVisit.asp 我还问了问他如果去加勒比附近的英属岛屿这个签证行不行，竟然说还要办另外的签证，郁闷死了 :(
另，如果在英国一个飞机场转机，比如从美国回中国，而有美国的有效签证是不用签英国的证的。具体如下：
If you qualify from one of the following exemptions you are not required to hold a Direct Airside Transit visa and may still benefit from the Transit without Visa concession
(1). you hold a valid US or Canadian visa who also hold a ticket to or from the US or Canada rounded via the UK. This will include a period of 48 hours after the expiry of the US or Canadian visa for those leaving the US or Canada to allow for those who choose to leave at the very end of the validity of their visa.
...
(6). You hold a diplomatic or service passport issued by the Peoples Republic of China
If you intend to change airports in the United Kingdom you will require a visit visa
4.申根签证。根据申根协议，只要你得到以下任何国家的旅行签证，你就可以前往其他申根国家: 奥地利，比利时，丹麦，芬兰，法国，希腊，冰岛，意大利，卢森堡，荷兰，挪威，葡萄牙，西班牙，和瑞典 (Austria, Belgium, Denmark, Finland, France, Greece, Iceland, Italy, Luxembourg, the Netherlands, Norway, Portugal, Spain and Sweden.) 。我是在法国驻纽约领馆办的签证。
法国驻纽约领事馆网站：http://www.consulfrance-newyork.org/us/visas/schengenvisa.htm
开门时间：9am-1pm，坐地铁绿线6号到77街，走到74街上的领事馆小楼。进门先关手机，安检，