Jill, even if a school does not have programs available to service younger gifted children, the information you get from testing them really helps you figure out a strategy for them. I think the easiest grade skipping is early-on (I had one kid skip 5th, one skip 4th, and one skip 2nd and by far the easiest was 2nd grade--4th was bad either). Already I dread my 4 yr old going through the alphabet AGAIN in kindergarten next year. One reason I'm anxious to test him is to collect documentation to skip K and go on to 1st grade. More meat there. We have no regrets about grade skipping (except some slight concern about skipping the bridging grade between elementary and middle...here, that's 5th grade, but it's different everywhere). The boys are physically less mature than their classmates, but have no problems with academics. I'm already worrying about when/how to orchestrate a second grade skip, at least for one son. Someday, we'll have to figure out what valuable programs they should do with "time saved" as Miraca Gross calls it. My husband says they should go abroad and do an intensive language study, or explore Europe and other places. So much time is wasted for the really bright kids if they stay where they are, and I find it makes my kids misbehave (when they're bored and unchallenged) and fear that later they would turn to substance abuse or wreckless teenager stunts if I didn't advocate for them now.
Early testing can help justify grade skips, can identify talent search programs (like the Davidson Institute, Johns Hopkins, Duke, Rocky Mt, etc.) that have counselors or distance learning opportunities. My 7 yr old took the Johns Hopkins talent search SCAT test recently and said, "Thank you, Mama, for letting me take that test!" afterwards. He was excited to take an above level test, something that finally approached challenging him and gives him an interesting experience. He can't wait to take other tests in the future. He's so happy to be a Davidson Young Scholar--it has really improved his self-esteem, and I also think it motivates kids to want to take distance learning courses or other opportunities.