Create Markdown hyperlink automatically. Usage: type ``:MDURL`` over a URL.

CreateMarkdownHyperLink.vim

" Create Markdown Hyperlink Automatically
" Requires mattn/webapi-vim (or vital.vim), tpope/vim-surround,
" kana/vim-textobj-user, mattn/vim-textobj-url
command MDURL call CreateMarkdownHyperLink()
command MDURLTitle call CreateMarkdownHyperLinkWithTitle()
function! GetWebPageTitle(url)
    let res = webapi#http#get(a:url)
    let dom = webapi#html#parse(res.content)
    return dom.childNode('head').childNode('title').value()
endfunction
function! CreateMarkdownHyperLinkWithTitle()
    let areg = @a
    execute 'normal "ayiu'
    let url = @a
    let title = GetWebPageTitle(url)
    execute 'normal viuS)i['.title.']'
    let @a = areg
endfunction
function! CreateMarkdownHyperLink()
    execute 'normal viuS)i[]'
    startinsert
endfunction

ブログの方でもコメントしましたが、こちらにも書かさせて頂きます。
使わさせて頂き加筆が楽になりました。ありがとうございます。
https://gist.github.com/nora75/bd3c5a58488baf1ba077efe88a06cdfa