This is a Li-ion/Li Polymer Battery Charger with ISL6292 which is an integrated single-cell Li-ion or Li-polymer battery charger capable of operating with an input voltage as low as 2.4V. This charger is designed to work with various types of AC adapters or a USB port.The ISL6292 operates as a linear charger when the AC adapter is a voltage source. The battery is charged in a CC/CV (constant current/constant voltage) profile. The charge current is programmable with an external resistor up to 2A.source

Here is a Lithium-Ion Linear Battery Charger with Thermistor Interface with the LTC4050-4.X from Linea technology.The LTC 4050-4.1 and LTC4050-4.2 are complete standalone constant-current/constant-voltage linear charge controllers for lithium-ion (Li-Ion) batteries. Charge current is programmable and final float voltage has ±1% accuracy.source

The circuit presented here comes as a low-cost alternative to charge mobile telephones/battery packs with a rating of 7.2 volts, such as Nokia 6110/6150.source

This is a charger for lithium ion batteries which takes its power from the USB port of a computer.It uses the MCP73861 or MCP73863 Li-ion battery charger chip manufactured by Microchip.The circuit is very simple to build based on the application note.source

This is a Lithium-ion charger for lipo batteries. Circuit schematic shows configuration for charging single 3.7V lipo battery but voltage can be set to charge several batteries in series. Lipo charger sets a current limit with the LM317, and 1 resistor, and the voltage limit with the TL431, and 2 resistors.source