Hi!
I just saw this project and first of all I want to congratulate all of you for this.
In the past I have implemented some neural networks algorithms (Elman, Self Organizing Maps and Learning Vector Quantization) for the WEKA environment (
http://www.cs.waikato.ac.nz/ml/weka/) so I could contribute to gneuralnetwork as well. The only drawback is my poor C programming skills/experience but I guess this wouldn't be a major problem.