Finally, I have came back to home with a lot of positive experiences in my OSG All Hands Consortium participation.
There, I had opportunity to meet interesting people with different background of knowledge.
The organizers invited me to participate in a session panel on March 5th.
The panel was developed as follows: every panelist has ten minute for presentation and three minutes for questions. We were six panelists in total.
My presentation was the third. I talked about my experience in Grid School at Brownsville, Texas in 2006, the personal benefits of participate there, advantages and disadvantages, and finally, I talked about my current work in PRAGMA, advantages and disadvantages of work with PRAGMA.
As conclusion of my participation, I realized in order to be understood for your audience, it's necessary have a good and large vocabulary and don't be concern so much about your grammar level.
For example, Anglo speakers, when they start speaking Spanish, have difficulties conjugating verbs, however, we can understand them with a little effort when they say something like that: "Mi tener un negro carro".
So, I'm sure that it's important know about grammar, specially when you write, however don't be shy at time to speak in public, the Anglo be nice with you and they recognize your effort.
However, it's a good idea write a script of your presentation. This backup make you more confident.