I've noticed that new users don't show up right away next to Latest Member indicator. Why is that? Can I make this indicator instantaneous somehow? Thanks.
They will not be displayed and counted until they are verified or approved (if you have e-mail confirmation on or need approval). Further, as someone already said (@Carlos) they populate throughout the day (every few minutes, so it is fairly fast).
However, if you're using the ever so popular add-on widget ( [bd] Widget Framework ), the results are cached and may take a little longer to display.