This paper presents the implementation of two routing protocols for Wireless Sensor Networks (WSNs): GRACE (GRAdient Cost Establishment for Energy Aware routing) and GRAB (GRAdient Broadcasting) along with their comparative analysis using Sun SPOT sensor nodes, developed by Sun Microsystems. The performance of both the routing protocols is evaluated on the basis of various performance metrics including network lifetime, throughput and network energy etc. However in papers where these routing protocols presented, practical limitations of wireless sensor nodes were ignored. The communication of sensor nodes is established using multiple communication channels for proper implementation of both the routing protocols, GRACE and GRAB. The experimental results show that GRACE outperforms GRAB in enhancing the network lifetime, while the throughput of GRAB is better than that of GRACE.