These are for bash shells, and may be Mac-specific also, and would go in .bash_profile or .bash_login or as marked specifically below:

1. Always open new terminal windows in the location of the last directory that you cd'd to (source: ):

pathed_cd () {
if [ "$1" == "" ]; then
cd
else
cd "$1"
fi
pwd > ~/.cdpath
}
alias cd="pathed_cd"

if [ -f ~/.cdpath ]; then
cd $(cat ~/.cdpath)
fi

2. Erase duplicate entries from command history (source: ):

export HISTCONTROL=erasedups
shopt -s histappend

3. Allow partial matching of previous history instead of scrolling back through full history (note this one goes in .inputrc, source: ):

1. do not make noise

set bell-style none

1. By default up/down are bound to previous-history
   
2. and next-history respectively. The following does the
   
3. same but gives the extra functionality where if you
   
4. type any text (or more accurately, if there is any text
   
5. between the start of the line and the cursor),
   
6. the subset of the history starting with that text
   
7. is searched (like 4dos for e.g.).
   
8. Note to get rid of a line just Ctrl-C

"e[B": history-search-forward
"e[A": history-search-backward

$if Bash
# F10 toggles mc on and off
# Note Ctrl-o toggles panes on and off in mc
"e[21~": "mcC-M"

#do history expansion when space entered
Space: magic-space
$endif

1. Include system wide settings which are ignored
   
2. by default if one has their own .inputrc

$include /etc/inputrc

4. Add status indicator for local changes to git or svn versioned directories (source: ):

1. Prompt setup, with SCM status

parse_git_branch() {
    local DIRTY STATUS
    STATUS=$(git status 2>/dev/null)
    [ $? -eq 1 ] || return
    [[ "$STATUS" == *'working directory clean'* ]] || DIRTY=' *'
    echo "($(git branch 2>/dev/null | sed -e '/^[^*]/d' -e 's/* //')$DIRTY)"
}

parse_svn_revision() {
    local DIRTY REV=$(svn info 2>/dev/null | grep Revision | sed -e 's/Revision: //')
    [ "$REV" ] || return
    [ "$(svn st)" ] && DIRTY=' *'
    echo "(r$REV$DIRTY)"
}

PS1='u@h:W$(parse_git_branch)$(parse_svn_revision) $ '

5. Misc aliases.

1. various ls aliases

alias ll="ls -lp"
alias la="ls -ap"
alias lla="ls -lap"

1. shorthand to search history, "h blah"

alias h="history | grep "

1. open current directory in finder

alias o='open .'

1. add all new files, which aren't ignored, to svn repo

alias san='svn status | grep "^?" | awk "{print $2}" | xargs svn add'