matching repeated character

looking for a bit of help with sed.

I have a file that looks a bit like this:

sdfghhjk
asdfdfghgj
asdfhgghj
werdfvtfh
edftbgh
1211211221
sdffgfm
dfghnhjm
dfvfsgbgh
adsfv bdhgn
1111111dffg
dfv1122
dsgvbghn111111
fffffffgbdghn
fffffff
sfgh3333gs vdf

I need to match any line that has a any character repeated more three or more times in a row.

so i need output like this:

1111111dffg
dsgvbghn111111
fffffffgbdghn
fffffff
sfgh3333gs vdf

Wow!

I would do that in C, I'm sure plenty would do that in AWK.

awk or sed is fine, i don't want to get in to C for this job.

sed -n 's/\(.\)\1\1/&/p' myFile

dude you rock!!

thanks.

Nice,
or even:

grep '\(.\)\1\1'