Handheld 2D ultrasound is very useful for intra-operative imaging, but requires some reconstruction effort in order to create 3D US volumes, unless one is using large and expensive 3D US probes. Common probe tracking approaches involve either global tracking mechanisms (suffering from jitter and complexity) or local tracking algorithms (e.g. image-based, suffering from drift). We propose to use a combination of local sensors to reconstruct the probe trajectory with multiple degrees of freedom. These sensors can be very low-cost - e.g. optical mice and a Wii Remote - yet enable simple 3D US acquisition with no global tracking overhead. The resulting trajectories can be used as input for 3D US algorithms or constrain image-based approaches.