This plugin is very much inspired by Tim Pope's pathogen plug-in. vim-ipi
adds the functionality of loading infrequently used plugins later. This
greatly helps in cutting down vim's start-up time.

Installation:
Install vim-ipi in ~/.vim/autoload (or ~\vimfiles\autoload), together with
pathogen (http://www.vim.org/scripts/script.php?script_id=2332).

Pathogen's settings can be used to configure ipi as well, e.g. disable
plugins (g:pathogen_disabled).

For loading plugins later, install them in ~/.vim/ipi (or ~\vimfiles\ipi)
and  add `call ipi#inspect()` to .vimrc. This will create a list of plugins
that can be loaded later by using the IP command:

Examples:
Load gundo plugin later:
:IP gundo

Load gundo and speeddating plugins later:
:IP gundo speedating

Load all known plugins later:
:IP!

A very high level of convenience can be achieved by loading the plug-ins
automatically right before using their functionality. Here is an example for
the gundo plug-in. I just prefixed the mapping with ":silent! IP gundo<CR>":
nmap <leader>u :silent! IP gundo<CR>:GundoToggle<CR>

Tips:
Some plugins use the autocommand VimEnter to do some initialization. ipi
has built-in support for a number of plugins that use this feature. A
detailed description is provided for the g:ipi_vimenter_autocommand
variable.  In case a plugin is not support yet, manual execution of the
autocommand can be done by running the following command:
:do <AUTOGROUPNAME> VimEnter

For the convenience wrapper it would look like this:
nmap <leader>f :silent! IP NERDTree<CR>:do NERDTree VimEnter<CR>:NERDTree<CR>