I'm curious:
Sometimes there are different events, when websites cannot handle their traffic. (usually starts at precise time until sold/booked/etc.)
For example:  

Class registration at schools,  

Sale of some super cheap stuff (for example $99 tablet pc on ebay: <http://techcrunch.com/2011/12/11/they-love-me-they-really-really-love-me/>),  

some other improtant registration (in my particular case this is a visa application (only 300 entries worldwide).

Often, websites do not respond very well when clicking submit button, pay button, or next step button in these situations. Are there ways or tricks to make your application more responsive.

The only ways I found:

1. Have good internet connection (Concerns about ISP provider? How to check latency or some other smart words?)
2. Have fast computer and browser (Any special settings?)

But these are all basic stuff. What really happens is that server just cannot handle all traffic (is there a queue? Should I press submit button multiple times? can I monitor somehow through firebug that my response was lost? there should be something!!)