NOVELTY - A fuel for a fuel cell, comprises a carbonaceous fuel substance; and a thickening substance that imparts viscosity to the fuel substance to form a gel fuel.    USE - For fuel cell used in mobile devices, e.g. mobile phones, or handheld and laptop computers.    ADVANTAGE - The invention provides a safe, easy to handle and of low-cost fuel.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for:    (A) a fuel cartridge for use with a fuel cell, comprising a compartment for holding a fuel suspended in a gel, and a fuel vapor permeable layer (FVPL) forming one aspect of the compartment;    (B) a method of supplying fuel to a fuel cell comprising providing a fuel substance suspending within a gel such that when contacting air, fuel is evaporated out of the gel, and directing the evaporated fuel substance into a fuel cell using a FVPL coupled to a fuel cell which fuel vapor permeable layer FVPL allows fuel substance to pass through it into the fuel cell;    (C) a direct oxidation fuel cell system comprising a direct oxidation fuel cell, a fuel supply cartridge, and an electrical coupling across the fuel cell for supplying power to an application device; and    (D) a fueling device for a fuel cell system, comprising an internal fuel compartment that contains a gel fuel coupled to at least one fuel cell in the fuel cell system for delivering a fuel substance that evaporates out of the gel fuel, and a replacement container coupled to the internal fuel compartment for refueling the gel fuel in the compartment.    The FVPL is permeable to a fuel substance that is released out of the gel, and the aspect of the compartment is coupled with the fuel cell in such a manner that the fuel travels through the FVPL into the fuel cell. The direct oxidation fuel cell includes a membrane electrolyte intimately interfacing with a catalyst layer along each of membrane's major surfaces, being a catalyzed membrane electrolyte, having an anode aspect and a cathode aspect. It also includes an effective water supply from cathode to anode within the fuel cell, so that water management in the fuel cell is achieved without water collection from the cathode and/or water transport from cathode to anode external to the active volume of the fuel cell.    DESCRIPTION OF DRAWING(S) - The figure is a schematic illustration of a gel fuel replacement cartridge coupled to an application device.