What are there four of?

I'm trying to create a new tattoo for myself - I don't expect my sibs to join in (though one of them does have a tat, and the other is planning on getting one) but I want it to honor the four of us.

One born in winter, one spring, one summer, one fall

So, what are their four of (and only four of - not four or more, just four)?

I've got: seasons, tarot card suits, playing card suits, horsemen of the apocolype, beatles (not really what I was looking for, but hey, good thinking on my bud's part, right?), four leaves on a four leaf clover (esp. cute for its resemblance to the shamrock, an universal symbol of our birthplace, Ireland), four provinances (another Irish referance - Ireland's counties are divided into four provinances)....

Help us out?

If I get the tat, there are pics in it for you guys! (Awesome bribe, right?)

American refs are equally appreciated; we were all born as recognised citizens of both the US and the ROI, but it's harder (at least for me!) to think of American icons in terms of fours.

I right away though of the four leaf clover (before I finished reading the post). I think that could be a really cute tat!

How about the four elements? Earth, water, air and fire.

I immediately thought of the Four Horsemen, but you've already mentioned that one.

The first thing that comes to mind is the Celtic Wheel of the Seasons.

I can't find any pics, but it's a Celtic knot cirlce made of interwoven tree branches, the foliage in each quarter represents each season (buds, leaves, red leaves and bare).

Guys, thank you so much!

What awesome ideas.

how about a four leafed clover? one leaf for each sibling?

numbers 1, 2, 3 and 4 in Japanese or Chinese

You could create your own totem with the seasons being represented.