Calling Guided Reading Groups

How do you organize for guided reading?  Now, I know that's a loaded questions because there is so much to plan for.  I am asking just about how you call your groups and how students know what groups they are in.  I am going to share my method, but I am on the lookout for something that might work better.
Paint chips come into play again.  I group my kids by color. They are actually grouped by reading levels at the moment, but they don't know that!  Since the groups are flexible and always changing, I need a way for my friends to know what group they are in and who is meeting that day.

On my dry erase board I have an A and a B.  During guided reading, my class works in centers except for the two groups I will be meeting with that day.  The A group is the group that comes immediately to the meeting table.   My guided reading time is very limited.  I am REQUIRED to meet with two groups in thirty minutes.  To maximize the time we meet, my B group has to be ready to go.  The B group doesn't work on centers. Instead, they have independent reading time until I finish with group A. If I had to wait for them to put center materials away, we would never meet. 

Anyway, here is what my board looks like.

I taped a piece of white card stock to the paint chip and laminated it.  Then, I stuck some magnetic tape on the back.  I just use a dry erase marker to write my friends' names on the white part.  Next to the letter A, I put the color group I will be meeting with first, with the B group being the second group I will meet with. 

I tend to have five groups.  I made a sixth orange card for random groups I pull for specific skills.  My other groups are flexible groups, but tend to stay together longer because we are reading novels or doing lap books, all of which take a while.  The orange card allows me to pull as I need to from the other groups to touch base with students I notice have a common need.  I'll meet with them once or twice to hit the skill or strategy in question.

In my guided reading area, I extend the colors to my folder bins and teaching drawers.  My friends have a guided reading folder to hold the materials we are currently working with.  I just printed a color card that I can write their names on.

Next to that, I have my drawers where I keep the teacher materials I need for each group.  It's an easy way to organize for the week.  I can just throw in whatever I might need and we are good to go.

So, that's kind of how I let my friends know who is meeting today and keep myself organized.  Do you have an easier, more effective way to do it?  If so, please share!  This has been working for me, but I'm always open to new ideas.