3.23.2 Greatest hits from previous weeks

Greatest hits from previous weeks:

3.23.2.1 Using \footnote in a figure's \caption

https://tex.stackexchange.com/questions/10181/using-footnote-in-a-figures-caption

Maybe this is an easy one, but I struggled with this now too long :) 
I want to have a footnote in a caption of a figure, see the example. 
\begin{figure}[!ht] 
\caption{a figure  ...
 

- asked by Matten (147 votes), answered by Herbert (94 votes)

3.23.2.2 How can I split an equation over two (or more) lines

https://tex.stackexchange.com/questions/3782/how-can-i-split-an-equation-over-two-or-more-lines

I am having the following equation: 
\begin{equation} 
Q(\lambda,\hat{\lambda}) = -\frac{1}{2} P(O \mid \lambda ) \sum_s \sum_m \sum_t \gamma_m^{(s)} (t) \left( n \log(2 \pi ) + \log \left| C_m^{(s)}  ...
 

- asked by Peter Smit (157 votes), answered by Will Robertson (113 votes)